Original subtitles

DAN SNOW: 'Deep in the English countryside

'lies one of the most famous ancient monuments...

'..Stonehenge.'

Stonehenge is totally unique.

There's nothing like this ring of colossal stone arches

anywhere else in the world.

It's as old as the Pyramids.

It's one of the world's greatest archaeological sites.

But who built it and why?

'How did ancient builders construct this extraordinary stone circle?

'For centuries, there have been so many unanswered questions

'about these stones.

'In this programme, I'm joining the investigations

'that are still unlocking the mysteries of Stonehenge.

'I'll be following the most recent hunt

'for where the biggest stones came from...'

There's some big ones up ahead.

Oh, yeah. Fantastic.

'..and exploring how they were moved.'

Well done, everyone. Give yourself a round of applause.

'I'll come face to face with the ancient people of Stonehenge

'and their beautiful treasures.'

Look at that. That's fabulous.

'And reveal the unbelievable sophistication

'of Stonehenge's builders.'

They knew their maths, they knew their astronomy.

That's why Stonehenge is unique.

And we'll never find anything like this.

This is the story of Stonehenge.

One of the things I love about Stonehenge is that one minute,

you're just driving through typical English countryside,

with its hills and its valleys and its fields.

The next minute, without warning,

boom, there's Stonehenge right there!

One of the world's greatest prehistoric sites.

'Built 2,500 years

'before Britain's first-ever towns or cities even existed,

'Stonehenge sits in the heart of the Wiltshire landscape

'on Salisbury Plain,

'three miles from the town of Amesbury.

'And once you're off-road,

'it still feels as wild as ever.'

When I was a kid visiting Stonehenge,

you used to drive your car right up and park next to it

and then clamber all over the stones.

And thankfully, that's changed now. It's much more special.

Much better for the local environment.

You park some distance away,

and then you walk across these beautiful downlands,

past these ancient, mysterious humps and bumps in the landscape,

evidence of a rich prehistoric past,

building your anticipation

that you're about to reach somewhere very special.

And then you arrive and see this.

Wow. You just don't get a sense of the scale of this place

until you walk inside these stones.

'You don't get a feel for its power, its intensity,

'until you're standing in here, right up next to them.

'And they dwarf you. Look at them, seven metres high.

'Each one of those weighs 20 tonnes.

'It just feels so ancient.'

And there's just nowhere else in the world like this.

Literally, there is nowhere else where we have stone circles

with these big stones placed on top, these lintels forming arches.

It's unique.

'These giant stones are just part of this awe-inspiring monument.

'Within this incredible ring of huge stones called sarsens,

'there are smaller stones,

'and these are known as the bluestones.

'And every one of the stones, big and small,

'have been carefully placed in position,

'and the entire stone circle

'is then surrounded by a huge bank and outer ditch.

'But unlike other great ancient discoveries,

'Stonehenge is different, because it was never lost.

'For thousands of years, it stood here,

'but people forgot what it was built for.

'And it became a magnificent mystery.'

The whole place is phenomenal,

and you find yourself thinking, "Who built it?

"Why did they build it? When did they build it?"

But above all, you think, "How did they build it

"with the technology they had available?

"How did they transport these enormous stones

"some distance to this place?

"How did they turn them on their end,

"sink them in the ground, anchor them?"

It's just mind-blowing.

'And all this happened thousands of years ago,

'before the wheel had even been introduced to Britain.

'So, 900 years ago,

'when people first began to speculate

'about how Stonehenge was created,

'they simply could not believe

'that the giant stones could've been put here by ordinary people.

'And they came up with a pretty wacky theory.'

This is an illustration of one particular popular account

of just how Stonehenge came to be,

and this account is literally magical.

You can see the stones being laid here

into the stone circle by a giant,

and it's not being built right here.

It's being built in Ireland

before being magicked here by the wizard Merlin.

'This fantastical tale may sound ludicrous today,

'but it shows how people have been grappling for centuries

'with the puzzle of how the stones got here.

'And it's still a hot topic of research today.

'I'm heading to the Ancient Technology Centre in Dorset,

'where they're testing out a possible theory.

'The weather is grim today,

'but that wouldn't have stopped our Stone Age ancestors.'

That's a pretty big chunk of rock, isn't it?

It is, yeah. It's about a tonne and a half.

Tonne and a half. OK.

'Antony Whitlock is an experimental archaeologist

'at the centre.'

It's sort of equivalent to some of the smaller bluestones

that we find at Stonehenge.

Scary to think this would be one of the smaller stones

today at Stonehenge, that's amazing.

What is it? A sort of sledge, is it?

Is this the latest thinking on how they were moved?

Yeah, absolutely. Yeah.

So it's based on stone carvings from Assyria and Ancient Egypt,

which are showing big statues being moved on sort of skis,

on runners, like we've got on the ground.

The old theory, which goes back to the 1500s,

was Stone Age people, prehistoric people,

moved stones on rollers, and that...

It works on flat, level ground.

But experiments since the 1950s have proven that big lumps of rock,

if they're being attempted

to move sort of uphill or downhill on rollers,

you lose control very easily, yeah.

'Once on the move, a sledge proved easier to control than rollers,

'although a little bit more difficult

'to get moving in the first place.'

So, you need a lot of force. You need a lot of force.

More than just D Snow can provide. Unfortunately, yes.

We're gonna need a little help. Mighty as you are.

'Luckily, we got an army of 50 volunteers on hand

'to flex their muscles.'

Grab a bit of rope. Let's divide in half.

Hope you're feeling strong.

'You can imagine the whole Stone Age community coming together,

'a bit like this, to help move the rocks

'to an important place like Stonehenge,

'with someone taking charge of the stone shifting.

'Today, that's me.'

Everyone feeling good? Here we go.

Ready?

Three, two,

one... go!

Going again, ready? OK, we're gonna try for another one here.

Ready? OK, everyone. Three, two, one... go!

Whoa! Look at that. It's moving.

'The wet, muddy ground certainly helps the sled

'slip along fairly easily.

'And Stone Age people might well have used the weather

'to their advantage in just the same way.'

DAN GRUNTS

OK. Stop, stop, stop! That was brilliant!

You're so strong. Well done, everyone.

Give yourself a round of applause. Look at that.

Well, that was a really interesting experiment.

It shows that it is possible to move a big stone

over some distance using this set-up,

provided you have a lot of people to help.

'With 50 people,

'we moved our stone a few metres quite easily,

'and archaeologists are now pretty certain

'that this is how Stonehenge's ancient builders

'moved the stones 4,500 years ago.

'But our stone weighed just one and a half tonnes.

'Stonehenge's biggest stones weigh 20 tonnes

'and were transported many miles.

'It's just incredible to think of the scale of that operation,

'the number of people needed to move one of the massive 20-tonne stones.

'The organisation needed to arrange them all here on the plain.

'Four hundred years ago,

'when the first person to really scrutinise the stones

'arrived on the scene, he was certainly impressed.

'Inigo Jones, the most famous architect of the time

'and a man who knew all about putting up stones.'

Jones was enthralled.

He was convinced this site had been put together

by very skilled master craftsman.

'He noticed that some of the stones

'had large chunks gouged out of them.'

This, he realised, fit neatly,

snugly on top of those knobs on the uprights.

'Someone had skilfully put these arches together

'like a huge ancient Lego model.'

There's only one people in his mind who it could be -

the Romans.

'Jones came up with a theory about what on earth Stonehenge was,

'that it was a Roman temple built around 2,000 years ago.

'He began to measure and survey every single stone

'to produce a plan to prove his theory.'

He knew that Romans built with a keen eye

for symmetry and proportion.

And this is the plan of the monument that he came up with.

Just look at it here. It's very intricate.

And it's perfect. A little bit too perfect.

Look, he's turned Stonehenge into an absolute circle.

All the stones smooth.

Exactly the same size, almost interchangeable.

And as you can see, the reality is a little bit more messy.

'In fact, if you overlay his plan over the stone circle,

'it's clear that Jones ignored the actual position

'of any standing stone that didn't fit the symmetry.'

Essentially, Jones's Roman theory only worked

because he... well, made it up.

'Jones had manipulated the evidence,

'but he had revealed Stonehenge's complexity and sophistication

'for the first time.

'It was now clear that these stones had been skilfully shaped

'and positioned, and people were captivated.'

Anybody who was anybody now came to look at these stones,

and that included the world-famous architect,

Sir Christopher Wren - and look, he left his mark here.

That is graffiti of his name.

A cross for "Christopher",

and then "Wren" here in this mighty stone.

'As more and more people came to Stonehenge,

'more theories were put forward about its origins.

'It was a royal Viking camp

'or perhaps a temple built by an ancient British priesthood,

'the Druids.

'No-one could agree, and no-one could find any proof

'to unlock the truth.

'But that was about to change.

'Three hundred years ago, the discovery of a buried clue

'would finally reveal the true purpose

'of these ancient stones.'

DAN SNOW: 'Stonehenge.

'For millennia, it stood isolated and ignored...

'..magnificent but forgotten.

'But then, 300 years ago, people were clambering all over it,

'as the best brains in the land tried to work out its secrets.

'So far, no-one had come close to solving any of the mystery.

'But that was about to change.

'In the summer of 1721,

'one man began to explore beyond the stones,

'in the land around the monument.

'His name was William Stukeley.

'He started to roam the surrounding landscape,

'eyes to the ground, searching for something,

'anything to help him understand Stonehenge's ancient past.'

As he was exploring this field,

Stukeley stumbled across something that felt familiar.

There was a depression, almost like a ditch

in the landscape, very difficult to see.

But with his practised eye, it was clear,

and there was some higher ground here on the other side.

It reminded him of the ditch and bank

that circled Stonehenge itself.

But the difference was this wasn't circular -

this was straight.

'It didn't make much sense.

'But then he noticed something even more intriguing.'

He walked across this field for another 30 metres

until he found another ditch, another bank.

You can see the line of it here.

And this one seemed to be parallel to the one he just discovered.

Could it be that they were marking out some kind of route

through this landscape?

And excitingly, that route seemed to be leading up to Stonehenge.

'Intrigued, Stukeley followed the course of the path.

'He was determined to find out how it was connected to Stonehenge.'

Stukeley quickly realised that the path was leading him up

to this big, prominent stone here.

And as he reached this stone and continued on the same line,

he realised that it was drawing him through that arch there,

right into the centre of Stonehenge.

Stukeley was ecstatic. That couldn't have been an accident.

Whoever laid out this route wanted people

to move right up into the heart of the monument.

'Stukeley was fascinated, and he had a convincing theory.

'He believed that he had found a sacred avenue

'leading right into Stonehenge.

'But what were those ancient people doing

'when they reach their destination inside the stones?

'He was now obsessed

'and spent days and nights in and around the stones.

'It was then, as he watched the sun rise and fall through its arches,

'he unlocked one of Stonehenge's most incredible secrets.'

Stukeley noticed something spectacular.

On the summer solstice,

the longest day of the year when the sun is highest in the sky,

the sun rose right above that stone, there, along the line of the avenue

and right through the middle of Stonehenge.

This couldn't be an accident. It had to be deliberate.

And that meant Stonehenge was designed

around the movements of the sun.

'Today, Skyscape archaeologist Fabio Silva is mapping the skies

'that our ancestors would have seen at Stonehenge

'to find out the precise astronomical alignments.'

OK, so, Fabio, what is a skyscape archaeologist?

It sounds like the coolest job in the world.

It is a little bit. We can use equipment like this to come here

and take the measurements ourself.

Put them on a computer.

Open up a planetarium software

that shows us what the sky looked like 5,000 years ago,

and put the stones against that sky.

'The alignment of the stars relative to the Earth is shifted slightly

'over the millennia since Stonehenge was first built.

'Fabio's finding out what the Stone Age sky looked like

'right here back then.'

So you can actually see the stars as they would have seen them?

That's right. Yeah, we can, we can.

It's close to what they would have seen it as we as we can today.

Stukeley suggested this place is solar aligned. He was right, was he?

Yeah. Absolutely. Absolutely. He was right.

So, he mentioned the midsummer sunrise alignment,

which is where the avenue joins up with the henge,

right where the heel stone is.

Cut Stonehenge in half, two exactly equal parts,

and this line exactly matches the midsummer sunrise on one end

and the midwinter sunset on the other.

These were master builders. They knew their maths.

They knew their astronomy.

They encoded everything they knew into this one place.

That's why Stonehenge is unique and we'll never find anything like this.

'All of this was over 4,000 years ago.

'That's just incredible to think about.

'Well, it's a bit cloudy, but it is winter solstice today.

'So to prove just how skilled those ancient Stonehenge builders were,

'as we approach a gloomy sunset,

'Fabio has asked me to help him take some measurements.'

All right, Fabio. What have we got? Hey. Show me the results.

Let's look at this.

Oh. So, what you're seeing is winter solstice around 2,500 BC.

That's fantastic.

Just as people would have seen it.

That is cool. So this is 4,500 years ago?

This line here is the sun, is it?

Yes. That's the that's the line the sun does on the day of the solstice.

OK. So we can see where it rises.

And then it's going to set right in the middle of that window

in the middle of Stonehenge.

So cool. You can imagine being here 4,500 years ago.

People coming up this... this processional route here,

and it would have just been in perfect alignment.

Yeah. That's right.

It's just the most extraordinary monument, isn't it?

The sophistication of that excellent visitor experience marching up here

on the shortest day of the year and seeing that alignment.

Absolutely. It's unique.

There's nothing like this in the world.

'Three hundred years ago,

'Stonehenge's solar alignment captivated people's imagination.

'As more and more visitors came and inspected the site,

'there was a real hope

'that more of Stonehenge's ancient secrets would be unlocked.

'But there was a problem with its popularity.'

Tourists were now beginning to put the stones themselves in danger.

They were coming here and clambering on them.

They were digging little holes around the place.

They were even chipping little pieces of the stones off

and taking them home as souvenirs.

'Then, on the third of January, 1797, disaster struck.'

A group of travellers was camping among the stones.

For some reason they dug a big hole at the base of one of them.

It was already looking a bit precarious.

As the sun came up, it thawed, the ground, soil became moist,

and with a great crash one of the stones fell over,

bringing down the ring of stones like dominoes.

'Luckily, many of the stones remained standing,

'but people worried the collapse of some of the stone circle

'might be the beginning of the end.

'Many feared that just as the secrets of Stonehenge

'were finally being rediscovered,

'the ancient monument was in danger of total collapse.

'The future looked bleak.'

DAN SNOW: '230 years ago.

'After investigations had revealed Stonehenge was designed

'to celebrate the movements of the sun, moon and stars...

'..disaster had struck.

'Some of the stones had collapsed.

'Stonehenge's future now hung in the balance.'

Many despaired.

Was this the beginning of the end of Stonehenge?

But others were more optimistic.

What if, in this tragedy, there was the opportunity for discovery?

All that was needed was someone who had money and vision.

Luckily, such a person was available,

living quite nearby in one of the poshest houses in Britain.

'Stourhead lies just 24 miles from Stonehenge.

'This palatial, stately home was owned by one of the wealthiest

'and most passionate treasure hunters in Britain,

'a fantastically rich banker, Sir Richard Colt-Hoare.'

This is Colt-Hoare's library, his study,

his masterpiece, one of the most magnificent in Britain

that he had added to the side of his great stately home.

In this room, he filled it with his books,

but also images and statues of ancient philosophers and thinkers

who would inspire him and his guests to emulate,

to channel the wisdom of the ancient world,

Colt-Hoare was determined to carry out the most detailed

and extensive survey of Stonehenge ever.

But this English gentleman was not get his hands dirty himself.

Luckily, he had just the man to do the hard graft.

'A local amateur archaeologist had been digging at Stonehenge

'around the recently fallen stones.

'Like Hoare, he had big ambitions, and together, they decided to launch

'the biggest investigation of Stonehenge there had ever been.

'And that meant investigating this entire area.'

When you visit Stonehenge,

you realise that the stone circle itself is actually

just a small part of a much larger, ancient, more mysterious landscape.

Dotted all around the hills that surround Stonehenge

are mounds like these ones here.

You can see three, and there's many more on the hills around me.

These are all a little bit different in shape and size,

but they all have the same purpose.

They're all burial mounds.

'They're called barrows.

'These had been found right across the British Isles,

'and treasure hunters had been looting them for centuries,

'so it was well known that they were used for burials.'

But nowhere had as many barrows of Stonehenge.

And so Colt-Hoare thought

that if some of these barrows were undisturbed,

he could excavate them and learn from the skeletons

and the goods within them

more about Stonehenge and unlock its secrets.

'Wasting no time,

'Hoare's team began their archaeological assault

'on Stonehenge's barrows.

'Their investigation was carried out with the speed and efficiency

'of a military operation.

'Sometimes, they would power through a whole barrow in a single day.

'After five years of slightly disappointing results,

'they turn their attention to this spot just half a mile away,

'overlooking the magnificent stone circle.

'Today, it's private land, but I've been given special access.'

Still feels so magic, so full of possibilities.

And it was in this mound here, right on top of the hill,

that they would make the most extraordinary discoveries.

'They called it Bush Barrow thanks to a small tree on its side.

'But there was nothing else particularly remarkable

'about this mound.'

I imagine they approached it with trepidation, with excitement,

as they always did when they started excavating a new burial mound.

But they couldn't have had high hopes,

given their previous experience.

How wrong they would be.

'With hundreds of excavated barrows under their belts,

'the team tore through the soil.

'After days of solid digging, they reached the bottom.

'And then at that moment, they made the discovery of their lives.'

At the base of this burial mound,

they found an undisturbed human grave.

A tall, stout man laid out north to south,

and the team gasped, because around him was

the most remarkable array of artefacts they had ever discovered.

Finally, they had struck gold.

'Today, the Bush Barrows skeleton and his magnificent treasures

'are held at the Wiltshire Museum in Devizes.'

So, this gives you an impression of what they found.

Yeah. This is a reconstruction of his burial.

'David Dawson has spent years unlocking the secrets

'of this incredible burial.'

You can see he's laid out in a crouched position.

He's got everything he needs.

Everything that shows how important he is.

So clearly someone of great wealth and probably of prestige and power.

Absolutely. And what do we know about him?

I mean, was he was he a tall man? Do we know how he died?

All we know is what the excavator said.

That he's a stout and tall man.

And he also gives the length of his femur.

So he knows he's a six-footer. He's a big chap. He's tall.

'The body is laid out with replicas of his personal items

'exactly as it was found 200 years ago.

'And those treasured goods reveal a person

'of incredible wealth and power.

'And the crown jewel in this collection

'is this extraordinary piece of gold.

'This decorative diamond shape

'that would probably have been worn on a cloak.

'It's not just beautifully crafted.

'Archaeologists have discovered something remarkable about it.

'They've worked out that the angles of the diamond

'inscribed on the surface

'precisely match the angle of the movements of the sun

'at the summer and winter solstice.

'They discovered that if you place the diamond

'in the centre of Stonehenge at the winter solstice,

'you can use it like a compass.

'If you align one side with the setting sun,

'you can work out where the sun would set

'during the summer solstice.'

It's 81 degrees. Wow.

So it shows an understanding of astronomy.

And then you see the zigzag lines around the outside.

Those are laid out to an accuracy of less than half a millimetre.

What that means is they understood geometry and mathematics,

accurate measurement.

To be able to construct that,

they had to understand those 4,000 years ago.

That is astonishing, isn't it?

For the first time, they were uncovering things

which showed the sophistication of people at the time.

'With the discovery of the bush barrow burial,

'we now had a glimpse of someone who'd actually known Stonehenge.

'His golden jewel suggests he was a sun worshipper,

'maybe even the person who oversaw Stonehenge's solstice celebrations.

'This man lived 4,000 years ago,

'at the same time as the Pharaohs ruled Egypt.

'And he was more magnificent, more wealthy,

'and more sophisticated than anyone had ever imagined

'Ancient Britons could be.

'With such remarkable finds,

'Stonehenge became more and more famous throughout the 19th century,

'and so, too, did the visitors.

'From Queen Victoria to Charles Dickens,

'Arthur Conan Doyle to Charles Darwin.

'But then disaster struck once again.

'In 1900, another of the giant stones

'fell during a violent storm.'

Enough was enough.

Stonehenge might be privately owned, but it was a national treasure.

It needed to be protected,

and that meant putting up the stones that had fallen down

and protecting those that remain standing.

They poured concrete around the bases.

They kept the lintels -

those horizontal arches - fixed on top of the uprights,

using lead taken from the roof of Hampton Court Palace.

'But the repairs gave archaeologists the chance to move in, too.'

They were determined to extract every piece of evidence they could

by digging in and around the holes

that had been left at the base of the stones that had fallen over.

They were gonna sift through the soil,

layer by layer, methodically,

and they didn't find treasure -

at least not gold or other precious metals -

but they did find antlers, charred wood,

and stone tools.

'The archaeologists concluded these were the ancient tools

'used to dig the ditch and shape the stones.

'But there was a much bigger revelation.

'Although metal had been found in the burials around Stonehenge,

'there was no evidence of any metal tools buried in the monument.

'Stonehenge had to have been built in the Stone Age.

'It was an incredible breakthrough,

'and the first step in solving the great mystery

'of when Stonehenge was built.

'Now, 100 years later, we can chart every phase of its construction

'from beginning to end.'

So, this is the, I guess, the first Stonehenge, if you like.

What's this? This is 5,000 years ago.

Yes, absolutely.

What it's showing us is the first things that happened in the space.

'Heather Sebire is the head curator at Stonehenge.'

They've dug out a ditch and threw up a bank,

with the contents of the ditch,

slightly higher on the inside and lower on the outside.

So, associated with the bank and ditch around the same period

are 56 pits.

And we know they hold cremation burials.

But as well as that,

the tops of the cremation burials were quite compressed

so, we're fairly sure they held posts of some sort. OK.

A lot of the academics who've done recent research

really do think they were probably bluestones.

So, these could be the famous bluestones

that are still on the site today. Absolutely.

So, more stones come in, but they're much bigger this time.

Quite the change. So, yes, absolutely.

And what they did was they erected five in a horseshoe shape.

Then, they form a circle, an arch, or circle,

enclosing that horseshoe shape.

So, it really is a feat of engineering.

So, all of these stones or posts

around the edge have gone, haven't they? Yes, they have.

Do you think they've taken the circle of bluestones

and put them inside there somewhere? Yes. Yes,

I'm sure they would have used the same stones.

So, it now feels it's all very much orientated towards the sunrise.

Yes, very much so.

So, it's been a bit remodelled. I can see that.

These bluestones have been moved around a bit.

So the bluestones get put into a circle,

and, really, an oval.

There's not major reconstruction at this time.

Nothing has changed

that will actually interfere with the solstice axis.

So, we're fairly sure that that's still very important.

So it's 4,200 years ago.

And the avenues here.

So, has this... Has this just been put in now?

Yes, indeed. So, really, this avenue, you know,

if you imagine a procession all the way,

like The Mall, you know, going up to Buckingham Palace,

it's connected Stonehenge with the river.

All the elements seem to have come together.

You've got the big stones being built,

you've got the solar alignment,

you've got the avenue joining it to other things.

This feels like its peak. Yes, it is.

'This precise dating of each phase,

'from simple bank and ditch

'to the big stones arriving.

'And then the construction of the avenue has only been possible

'to work out recently because of modern science.

'Back at the beginning of the 20th century,

'investigators were still beginning to feel more positive than ever

'about solving Stonehenge's mysteries.

'Until suddenly, 100 years ago,

'Stonehenge's future was suddenly thrown into doubt once again

'as it came into the firing line

'of the most devastating war the world had ever seen.'

DAN SNOW: 'Today, Stonehenge stands peacefully and protected

'at the centre of a vast 6,500-acre World Heritage Site.

'But every now and again, that peace is shattered.'

It may seem incredible, but one of the most precious

and important ancient monuments in the world

shares its home with the biggest

and busiest military training facility in the UK.

It's where the British Army has been coming

to prepare for battle for over a century.

Today, luckily, the helicopters and tanks

are kept to a safe distance.

But 100 years ago, it was a very different story.

'In 1914, Britain entered World War One.

'Suddenly, the vast training ground around Stonehenge

'was home to thousands of troops preparing for combat.'

Stonehenge found itself

almost literally at the centre of a battlefield.

This whole area was given over to training artillery, big guns,

as you can see from this dramatic front page of a newspaper from 1915.

You can see here the King himself

inspecting a troop of horse artillery,

as their guns are dragged right past the stones,

each of them weighing tonnes.

And then when those guns fired,

they might not have been aiming at the ancient structures,

but the reverberations, the shock, would have carried for miles.

'And the big guns weren't the only threat to the stones.

'Stonehenge was now also at the centre of a military airfield,

'with aircraft buzzing above it.

'It was said that as the pilots trained,

'they'd show off by trying to brush the tops of the stones

'with their undercarriages.

'Stonehenge had a turbulent time.

'But after the war, investigations picked up like never before.

'Now archaeologists and military pilots

'began to work together,

'taking and sharing aerial photographs

'over this landscape in the hunt to understand Stonehenge.

'And in 1926, that would result in an incredible discovery

'near to the monument.'

Look here, just in this field here,

you can see this circular shape with lots of black dots.

There was something hidden, buried in the ground.

'Analysing the photo in the 1920s, the archaeologists were astonished.

'The circle was almost exactly the same size as Stonehenge,

'and the dots seem to be symmetrically placed,

'just like the stones at the monument.'

Just imagine how excited the archaeologists must have been

when they entered this field.

Were they about to discover

the foundations of another Stonehenge

just beneath their feet?

'They started digging outside the main circle.'

It soon became clear -

the dark, circular impression was the remains of a ditch

like the one at Stonehenge.

And next to it was a circular bank.

I'm standing on it now.

This was almost exactly the same size

as the one at Stonehenge, 360 feet in diameter.

'But it was when they started to dig inside the circle

'that they found something even more intriguing.'

Fairly soon, they found a pit,

which was exciting because they knew from Stonehenge

that the stones didn't just sit on top of the ground,

they were sunk into them, in pits, to make them far more solid.

So a pit here suggested a similar structure,

but this pit was smaller,

and there were residues of wood in it.

So archaeologists assumed that,

unlike Stonehenge, this was made out of wood.

Huge wooden posts stretching up out of the ground,

perhaps 20 metres high -

twice as high as the biggest stones in Stonehenge.

Today, this marks the site of a pit,

but I should say pits,

because after finding that first one,

they went on to find pit after pit after pit,

until they realised that this was a whole landscape

covered in 168 tall, wooden columns,

soaring up to the sky, visible for miles around.

'And when the archaeologists looked at the layout of the monument,

'they noticed something very familiar.

'The columns were aligned with the movements of the sun.

'So how was this Woodhenge connected to Stonehenge?

'Was it an early wooden prototype?

'For 80 years, no-one had the answer.

'Until, in 2004,

'a new investigation finally revealed the truth,

'and it would revolutionise our understanding of Stonehenge.

'A team from Sheffield University set up base here by Woodhenge

'and began to dig.

'As they dug, they revealed that there was a physical link

'between here and Stonehenge.

'The avenue at Stonehenge was connected to the river.

'As it passed near Woodhenge, the avenue then picked up again.

'This was clearly a route between the two monuments.

'Stonehenge and Woodhenge were linked in the Stone Age.

'But this amazing discovery

'was just the start of their breakthroughs.

'What they found next in the area by Woodhenge,

'called Durrington Walls, was totally unexpected,

'and it was the real game-changer.'

As they dug their trenches right across this site,

they found layers of clay, and on them, burn marks.

It looked like people had been gathering around fires.

To the trained eye of an archaeologist,

it seemed likely that these were hearths

and that they had found Stone Age houses.

But as they realised the true extent of the finds,

it became clear that this was a whole Stone Age village.

'To see how our ancient ancestors lived,

'a replica of one corner of this rare discovery

'has been recreated near Stonehenge.'

Look, I love how picturesque and cosy the little hamlet feels.

Very different to the stark stone of Stonehenge.

Mm. Well, these are your classic wattle and daub houses.

This is the way that most people in Britain lived

up until about 500 years ago.

'Mike Parker Pearson led the team who discovered the houses.'

Well, what we've got is very simple construction,

that you have a screen of wood and then plaster against it,

wattle and daub,

and then you have reeds to build the roof.

That's amazing. They're all different, aren't they?

They're not all built to one particular almost...

No. Why is that?

What was really interesting is that

they actually form a module, a group.

Although each of them was a habitation with beds,

they had slightly different purposes.

That's the main house.

The storehouse round the corner.

We're standing just behind the cook house. OK.

And that's the workshop.

So, they're all working together as a single unit.

'Mike believes that each cluster of buildings

'was probably home to 15 to 20 people,

'all working together,

'possibly extended families.

'He believes that the whole Stone Age site

'would've been densely packed with groups like this.'

We have maybe a thousand houses.

A thousand houses?! Yes.

So this would've been perhaps

the biggest settlement in the whole of Britain.

Wow.

And do you think that's because of Stonehenge?

Undoubtedly.

The date for the occupation of this great settlement

is the same as the second stage of Stonehenge,

when the really big sarsens went up.

So, my guess is that this would've been

where the building crew were actually living.

That's almost a Stone Age city. Mm.

'As a result of the excavations,

'Mike has come up with an exciting new theory.

'The houses were found next to Woodhenge.

'Could that mean that together, they were a place for the living,

'and Stonehenge was a ceremonial site for the dead?'

It all seems to fit together quite nicely.

Stonehenge was the place where the people living

down at Woodhenge could come and commemorate their ancestors.

'At the summer and winter solstice, people would begin to gather

'at the Durrington Walls town next to the Woodhenge,

'before making their way up the sacred avenue to Stonehenge,

'where they would celebrate their ancestors

'at special times in the year.

'But then the surprise discovery of an ancient skeleton

'would reveal an even bigger story,

'putting Stonehenge at the centre of the ancient world.'

DAN SNOW: 'Stonehenge -

'By the 21st century, we were in the digital age,

'and science was revealing Stonehenge's lost secrets

'like never before.

'The sophistication of its solar alignment

'and the precise dating of the monument

'were finally becoming clear.

'And when the homes of Stonehenge's ancient inhabitants

'were discovered in 2004...

'..archaeologists found evidence of scraps of food,

'perfect for scientific analysis.

'And it revealed something incredible.

'There were traces of hazelnuts,

'fruit, honey,

'even a sort of ancient cheese, a bit like mozzarella.

'But there was one thing that dominated the menu.'

There are tens of thousands of pig bones from the site.

About 90% of all the bones that were found there are from pigs,

so they really like their pork.

'Archaeologist Richard Madgwick analysed the food

'and was fascinated by the amount of pig being consumed.'

'In his experience,

'this didn't look like an everyday menu.'

These were huge feasting events, in my opinion,

not only because of the volume of material,

but also because of the volume of pigs.

Cos pigs are good feasting animals.

You can kill large numbers

without harming what we call a secondary-product economy.

So, if you rely on milk, if you rely on wool,

you don't want to kill large quantities of cattle and sheep

in one go because you'll have nothing to live on afterwards.

But pigs don't have those products,

and therefore, they're very well suited to feasting.

Wow, so we can imagine the people at Durrington Walls,

they're there for a party,

and there's just a huge pig base, like the end of an Asterix book.

Yeah, I think you can think of it a bit like that.

'Richard now began analysing

'chemicals in the pig bones called isotopes.

'These would help him work out where the pigs had come from.'

So, if we're prepared to sacrifice a tiny fragment of a pig tooth,

20mg of an animal. Yeah.

Can you see that cut there? They took that half, yeah.

Exactly. That is an archive of lots of important information

about where the animal came from,

what its diet was like and how it lived.

So, every time we consume food and drink,

and animals consume food and drink,

chemical signals from those products enter the body,

and ultimately, and thankfully for archaeologists,

end up in our bones and teeth.

So what, so you can kind of identify where these animals are from?

To some degree, we can.

So, if I can show you a graph,

so we can see this square down here

is the chalkland and the greensand of Wessex

around the area of Durrington Walls.

And these blue diamonds here are the Durrington Walls pigs.

So lots of them are coming from fairly nearby.

Lots of them are coming from fairly nearby.

These that are below the 709 line and just above the 709 line,

they're consistent with being local.

'But the science also shows

'that pigs were being brought here from further away.'

But you can see we have got large numbers that are higher,

much higher up in the map, 710, 711,

all the way up to 717.

Now, these are really high values, and it clearly points to the animals

having come from a wide range of different locations,

different geological zones.

Certainly Wales,

certainly South West England

and certainly the eastern seaboard as well.

So people were coming from a long, long way,

and they're bringing their pigs with them. Wow.

'The pig bones revealed that Stonehenge was not only celebrated

'with a massive communal feast,

'but was the heart of a vast prehistoric network,

'drawing crowds from right across the land.

'But what about the origins of the actual people

'who were coming here at that time, 3,500 years ago?

'In 2002, a chance discovery

'was about to reveal an extraordinary clue.

'Just three miles from Stonehenge lies the town of Amesbury.

'Twenty years ago,

'a brand-new school was being built here.

'But just as construction started, work was suddenly halted.'

Any time that anyone tries to build something new around here,

they have to be very careful, indeed,

because we're so close to Stonehenge

that there is very likely to be precious archaeology

just beneath the surface.

So, when they were building this school 20 years ago,

archaeologists were on hand for every single moment.

And it's lucky they were,

because just over there where that playing field now is

they discovered one of the most important,

one of the richest burials ever found in Britain -

the Amesbury Archer.

'I've come to Salisbury,

'where the skeleton and his extraordinary grave goods

'are on display.'

This is one of the most significant prehistoric finds

ever made in Europe.

It's an adult male, around 35 to 45.

He was five-foot-eight tall, missing a kneecap,

so he'd have walked with a limp.

He's buried with his beakers there he might've drank beer out of

and an extraordinary rich array of other objects laid out around him.

He's got arrowheads,

and he's got a wrist protector just here

so that the string from the bow doesn't graze him as he releases it.

And he's been named as the Amesbury Archer as a result.

'But the archer had something else buried alongside him,

'and it's what makes this individual truly exciting.'

Alongside the archery equipment,

very unusually, is this.

Might not look like much, but it is a portable anvil,

a stone which he would've used to shape metal.

You can see examples of the sort of work he might have done just here,

these golden ornaments,

possibly used in hair, to tie up braids.

And also, you've got copper knives.

These gold and bronze objects

are the oldest ever found in Britain,

which means the Amesbury Archer

could be one of our first metal workers.

'The other finds in the grave are equally intriguing.

'Lying around him were five pottery cups

'called bell beakers because of their bell-like shape.

'This style wasn't local, it came from the continent.'

Archaeologists were very keen to find out

where this trailblazing individual might have come from,

and luckily, they now had the scientific tools

to do just that.

'I'm heading to the Natural History Museum in London,

'where scientists have been analysing the Amesbury Archer

'in extraordinary detail.'

So, Selina, you've got this mysterious character.

He's absolutely dripping with all the new technology and cool stuff.

Who is he? What have you boffins been able to unlock about him?

So, yeah, we actually know quite a lot about this individual.

He is a really interesting chap.

'Selina Brace is an expert

'in discovering the secrets of our ancient ancestors

'from minute information stored in their bones and teeth.

'The Amesbury Archer is full of a wealth of data

'about where he came from.'

Well, there's lots of different lines of evidence

that we can use to explain more about who the Amesbury Archer was.

One of the lines of evidence that we look at is isotope analysis.

So they looked at the isotopes in his teeth.

'It's the same science that showed us earlier

'that the slaughtered pigs came from all over Britain.

'By looking at chemicals in human teeth,

'you can also find out where someone grew up.'

So what's all that telling us?

So what this actually tells us is that his...

The signature that we see in his teeth

is not what you would expect from Britain. Ah!

So... Where's he from?

Well, it looks like sort of Central Europe. Wow.

Germany, Hungary, Austria, but he probably grew up in the Alps.

So he's migrated from the Alps to be buried in Amesbury.

Wow, much nicer climate. That's right.

I don't blame him.

Well, we think that he must have just migrated here.

Probably with a community, a whole group of people.

Because this is a time point

when we see a lot of migration happening in Europe

and a lot of people migrating into Britain at this time.

Wow, so even...

We think of the modern world, we're travelling around,

lots of migration going on,

but actually, this was people moving across Europe

even thousands of years ago.

Yeah, I mean, this was... Well, so he died 3200BC.

And yeah, there are huge swathes of people moving around Europe,

bringing different cultures, exchanging ideas.

Yeah, it's a pretty active time point.

'With the discovery of the archer's continental origins,

'his extraordinary burial goods made much more sense.

'Metalworking developed in Europe before arriving in Britain.

'Those jars, called bell beakers, were also a continental style.'

The idea of travelling many hundreds of miles to come here

is just remarkable.

And if people were making that big trek,

it implies that news of Stonehenge

must have spread far and wide.

'Modern science has transformed our understanding

'of Britain's most iconic monument.

'But until very recently, there was still one very big question

'that had never been answered.

'Where did the biggest stones themselves come from?

'In 2017,

'that mystery was finally about to be solved.'

DAN SNOW: '2017. Stonehenge.

'After hundreds of years of investigation and speculation,

'modern science was finally unlocking the secrets of the stones.

'But one of the greatest mysteries still remain.

'Where did the biggest stones,

'the sarsens that form these iconic arches, actually come from?

'Investigators had never got close to revealing the truth...

'until now...

'..when a lost piece of evidence emerged.

'Archaeologist Sue Greaney was part of the team

'given this incredible opportunity to identify the exact spot

'where Stonehenge's largest sarsen stones came from.'

So, Sue, how on earth do you work out where a stone is from?

Well, actually, sarsens are really, really tricky

to tell where they're from... I'm not surprised.

..because if you look at sarsen inside,

it's just like sand.

It just looks like solidified sand. OK.

That's because it's more than 99% silica.

So, actually, you have to use geochemistry.

You have to take a sample,

and you have to look at the trace elements,

everything that's not silica, in order to be able to match it.

It's sort of like a fingerprint or a signature.

So you're just looking at the chemical composition of the stone

using very whizzy technology.

'By matching the chemical signature of these mammoth stones

'with the identical fingerprint

'of ones found naturally in the landscape,

'scientists hoped they could work out

'where these stones originally came from

'before they were set up at Stonehenge.

'But they had a big problem.

'They really needed a stone sample,

'and that would mean hacking out a piece

'and destroying a bit of this precious monument.'

The "destroy" bit I can imagine is tricky with Stonehenge. Yes.

We don't want to be drilling into the stones here at Stonehenge.

'But back in the 1950s, engineers had done exactly that.

'To stop this stone from cracking,

'they drilled a hole and pinned it together.

'The core they removed was taken away to the United States

'by one of the team

'and forgotten until 2017,

'when it was returned out of the blue.'

Oh, wow, look at this! And here...

Wow! I love it. ..in this Perspex tube is the core.

So it's about a metre-long section,

complete cross section through the stone.

And if you look at it, you can see it's kind of like layers of sand.

It's a bit like one of those things you buy as a souvenir...

On the beach. ..at the beach, yeah.

That's perfect, isn't it?

And this bit here is where a little piece of it

was sent away for destructive analysis

so that we could look at the chemistry

of this particular stone in detail.

And you don't feel like you're desecrating an ancient site.

No, exactly. Cos it's already been taken out.

'Finally, Sue and the team

'had something they'd only ever dreamed of,

'a sample they could send to the lab and analyse its chemical signature.

'But now came the difficult part.

'They were gonna have to scour the countryside to find a match.

'They started searching within a ten-mile radius of Stonehenge.

'Susan is taking me on a trip through Wiltshire

'to retrace their steps.

'It's soon clear why this was such a mammoth task.

'The area is littered with natural sarsen stones.'

So, these are stones. Are they the sarsen stones we're here to see?

They're not.

This is a natural sarsen spread, sometimes called a sarsen river.

And this is exactly how it occurs.

Here, they're quite small,

but this would have been a common sight

across lots of bits of this part of Wiltshire.

'But when these stones were sampled,

'their chemical signatures didn't quite match Stonehenge's

'precisely enough.

'The hunt was still on for a better match.'

Wow. Right, let's keep going.

Just up here? Yep, up to the right here.

'The investigation now took the archaeologists

'deep into West Woods, eight miles from Stonehenge.

'This is where they'd make their breakthrough.'

So, I'm starting to see stones poking up through the surface.

Yeah, we've got just a few of them here.

There's a few, aren't there? There's some big ones up ahead.

Oh, yeah. Fantastic.

That's good. There's some of good size.

I mean, that one you could almost make a lintel out of, couldn't you?

'These stones were around the right size

'to be candidates for the ones chosen for Stonehenge.

'The archaeologists began to analyse them.

'Could this be the exact spot

'where Stonehenge's mighty stones originally came from

'around 4,500 years ago?

'The archaeologists carried out preliminary field tests.

'This is a machine that scans beneath the surface

'to identify the chemical composition of any material.

'Metal, wood, or stone.'

And it basically is an X-ray machine.

We just turn it on,

and we place it near to the surface that we want to analyse

and fire it away.

And then we just place it against the rock,

and... we just take the reading.

MACHINE BEEPS And it's done.

And we can look at that back in the lab and download the data.

And, yeah, you can just see here a little graph

of the reading we've just taken.

And so we've got that graph for the stones at Stonehenge? Yes.

And if it's the same graph,

then the stones are from the same place. Yes.

'When the archaeologists first analysed everything in the lab,

'the results were remarkable.'

So the sample that was taken from West Woods, which is where we are,

was the closest match to that signature,

that wiggle matching of all the chemical composition

of the sarsen stones at Stonehenge.

And so the scientists were happy that the sarsens from Stonehenge

came from here.

'It's an amazing discovery,

'proving that 4,500 years ago,

'the builders of Stonehenge came right here

'to this exact spot in West Wood

'to choose the biggest and best stones for their great creation.

'Sue's team could now work out the route they travelled to Stonehenge.

'These 20-tonne stones were dragged from West Wood

'over eight miles of rough terrain,

'out of this wood,

'down hills alongside the river,

'then uphill to their final destination on Salisbury Plain.

'The scale of the operation was incredible.'

It's just extraordinary to think that over 4,500 years ago,

our Stone Age ancestors were foraging in some woodland,

when they came across these mighty stones.

They decided to shape them and dig them up and transport them here

and then erect them into this huge monument.

And then for centuries afterwards, people from across Britain,

and as far afield as Europe perhaps, came here to visit.

And even now, millennia later,

it's drawing bigger crowds than ever.

'Stonehenge's discoveries are remarkable.

'They've revealed when it was built - 4,500 years ago.

'They've revealed the extraordinary story of how it was built -

'dragging those mighty stones here,

'carefully shaping and erecting them to align precisely

'with the movements of the sun.

'Then creating that avenue, linking it to Woodhenge

'and that vast Stone age village.

'And discovering what it was used for -

'thousands came here to celebrate the summer and winter solstice

'for over 1,000 years,

'journeying across the seas and the country...

'..burying their dead around it.'

It's taken three centuries,

armies of archaeologists,

investigations from the sky and looking under the ground.

It's taken the latest scientific techniques.

And yet now finally, it feels like we've unlocked

some of Stonehenge's most important secrets.

It's still one of the greatest,

one of the most magical archaeological sites on Earth.

But it's no longer quite as much of a mystery.