Original subtitles

(orchestral music)

Mastrelli: Stonehenge, a marvel of prehistoric architecture,

An imposing edifice that has dominated

Britain's salisbury plain for more than 4,000 years.

For centuries archeologists have been piecing together

Its history, but the reason for its location

On this remote chalk plateau, remains an enigma.

Why did this isolated spot become the focus

For an entire 80,000 square mile island?

Why did it spark one of the biggest building programs

Of the ancient world?

Now, after 15 years of investigation

A team of experts believes it has found the answer.

For centuries, the mysteries

Of the past have kept their secrets,

But there are clues.

Cast in gold, etched in stone, written in blood.

We can unlock them.

(upbeat music)

Stonehenge.

It's the world's most famous stone age monument

With standing stones tipping the scales

At 25 tons apiece, about the weight

Of a fully-loaded garbage truck.

Other stones at the site,

The smaller two to four ton bluestones,

Are relative lightweights, but, this just in,

Their precise source has now been identified

And it's two quarries 160 miles from stonehenge.

And this.

This nicely-polished piece of stone comes straight

From one of those quarries.

In the mountains of preseli in north-west wales.

(light music)

More than 1.3 million visitors are drawn

To stonehenge every year.

It captivates everyone, from tourists to presidents.

Obama: How cool is this?

Mastrelli: Even after 4500 years

This immense structure remains breathtaking.

Pryor: Stonehenge is still a magical place

Even though we don't really understand

The exact ideas behind it.

It still exerts this extraordinary attraction.

You can see it as you approach it

And you get a feeling of awe.

And you just want to walk towards those stones,

You want to be within those stones.

Mastrelli: What stands today on salisbury plain,

A windswept outpost of south west britain,

Is the remnants of a giant circle of standing stones,

Some are as heavy as 30 tons, dragged some 25 miles

And winched into place 4,500 years ago.

Within the circle are smaller stones,

The older blue stones, a series of more than 50 monoliths,

Each weighing over a ton,

Carried more than 150 miles from wales.

Through hundreds of years of investigation

Archeologists have managed to trace the development

Of this colossal endeavor from a simple stone circle

Made of just the blue stones

To the complex structure completed 400 years later.

Each element of the monument seems deliberately positioned,

Carefully tuned to one event: The mid-winter sunset.

Pryor: The mid-winter solstice is crucial

Because it tells you there's hope.

The days are going to get longer.

The crops will grow.

Mastrelli: Directly in front of stonehenge

Is a broad ancient avenue,

Originally cut into the chalky landscape.

This neolithic road is believed

To have served a ritual purpose.

A pilgrim's walkway leading ancient britons

Towards the monument on the evening

Of the shortest day of the year, the winter solstice.

Pearson: This may have been a huge procession.

Groups of maybe hundreds or even thousands

Of people moving along here on mid-winter's day

To see that extraordinary moment of the sun dying

For the last time, going below the horizon,

Framed by their fantastic monument.

Mastrelli: But what really intrigued archeologists

Is the monument's baffling location.

A lonely few acres of windy moorland

In a landscape of over 80,000 square miles.

Pryor: For centuries people have been asking,

How did they build it?

And what we're more interested in today is the far bigger,

More difficult question, and that is, why did they build it?

What motivated them to take that enormous amount

Of effort and why do it here?

Mastrelli: For stone age man,

This windswept corner of salisbury plain,

Was britain's most important site for pilgrimage.

But the mid-winter sunset could be celebrated anywhere.

So, why build a monument here?

(orchestral music)

For archeologist, mike parker pearson,

This question has become an obsession.

And, to answer it, he has delved further back in time.

To a moment before the giant stones had even been erected.

Remarkably, his main lead comes

From a 100-year old excavation

Of some 56 neolithic-era pits that encircle the site.

Back in 1919, the only scientific conclusion

That archeologists could draw

Was that each pit contained cremated human remains.

So, in the absence of superior forensic methods,

The excavators chose to rebury their finds

Under a single lead plaque.

Now, a century later, mike parker pearson has permission

To exhume those bones again.

Armed with incredible advances in scientific analysis,

He hopes the remains will hold the key

To stonehenge's very existence.

Pearson: You can imagine, my heart was in my mouth

As we got down to that layer and then, disaster!

Mastrelli: The bones buried beneath a lead plaque

Turned out to be an archeological nightmare!

Pearson: They'd all been completely scrambled.

The whole deposit was clearly completely mixed up.

Mastrelli: Parker pearson and his team were faced

With perhaps the greatest archeological jigsaw puzzle

Of all time!

Pearson: We've only had about half a million fragments

Of human bone, many of them burnt

And twisted and shattered out of shape,

But the information we knew was in there.

Mastrelli: The formidable task of making sense

Of this ancient mess would fall

To osteoarcheologist, christie willis.

Willis: When I saw the enormous amount of human remains

That came in from stonehenge

What was going through my mind was just

How incredibly difficult this task was going to be.

Mastrelli: It would take almost a decade

Of painstaking work to decipher the 500,000 fragments.

But now a picture is beginning to emerge.

The evidence suggests that long before it became a place

For the living to celebrate,

The stonehenge landscape was devoted to the dead.

Mastrelli: The 4,500 year history of stonehenge

Is being reshaped

Thanks to the exhumation of half a million fragments

Of ancient human bones.

That's a seriously big number

And it could do with a little perspective.

This jigsaw puzzle has five thousand pieces.

And, terrifyingly, comes with a easy-to-decipher picture

That lets you know what it should look like when it's done.

Now, imagine it's your job to complete 100 of these puzzles.

But, this time,

There's no picture on the box.

It took ancient bone expert christie willis almost 10 years

To complete her bone puzzle, but it was worth the wait.

The picture that has emerged from those 500,000 pieces

Has transformed our understanding of stonehenge.

The size of this burial ground is unprecedented

In stone age archeology.

But its age has left archeologist astonished.

The earliest bones were buried around 3,000 bc!

That's 500 years before stonehenge,

As we know it today, was even erected.

Willis: These results, not only did they rewrite

What we knew about stonehenge, but they rewrote

What we knew about neolithic britain,

Because stonehenge is now one of the earliest

And largest cremation cemeteries from neolithic britain.

Mastrelli: Could these burials

Be the very reason stonehenge exists?

Was this vast cemetery the motivation

For the construction of the monument?

To find out, archeologists need to understand

The nature of the burial ground,

Who was buried here and why?

Neolithic burials often show the scars

Of stone age existence.

A life spent under the constant threat

Of violence and disease.

Pearson: Prehistoric britain, particularly the neolithic,

Could be a fairly dangerous place.

Going on the evidence from earlier in the neolithic

Where we've got arrow heads stuck in bone,

Where we've got skulls smashed in,

You might expect something like

That amongst the cremated remains.

Mastrelli: But there was something special

About these bones.

Willis: Given this many cremated remains I would have expected

To see at least one form of evidence

That there was some kind of a violent conflict.

Evidence of arrowheads and of spears coming pass

Through the body, hitting the bones,

Deflecting off the bones.

There is just no evidence of any kind of violence

On these bones.

Mastrelli: The bones showed no sign

Of trauma related to violence

And neither did the burials show evidence

Of disease like a plague or epidemic.

Willis: We don't have a lot of children.

We don't have a lot of older individuals

And these would be the people that would normally go first

In an epidemic because they are

The weakest members of the society.

On the whole, these were very physical people,

Used to labor, they're also incredibly healthy.

Mastrelli: The stonehenge burials

Were remarkably free of the ordinary damage

Found on stone age skeletons.

And there was something else that set these burials apart.

Willis: Looking at the examples of bones we have here,

The majority of bones are actually quite big.

But we also have incredibly small bones.

Even the most minute bone was picked up for burial.

So, this tells us something about

How they honored their dead.

Mastrelli: Each burnt fragment of bone buried

At stonehenge had been meticulously collected

And treated with the greatest of care.

It suggests that what linked to the burials was the status

And respect these people commanded in life.

(mysterious music)

The recovery of chemical information

From burnt bone used to be impossible.

But forensic archeologist, dr. Christophe snoeck,

Is spearheading an attempt to extract crucial information

That may be trapped in these scorched skeletons.

He's searching the bones for a strontium signal,

A chemical that enters the body through food

And whose variations reflect the geology

Wherever a person lived.

It would mean he could identify exactly

Where in britain the bone was formed.

Snoeck's pioneering work proves, far from destroying it,

That high temperature burning may have actually preserve

This precious data within the fragments.

Snoeck: When bone is buried in the soil

A lot of chemical elements

From the soil can go in the bone and others can come out.

But when cremated the structure changes

And actually all the signal is locked

Into the cremated bone for thousands of years.

Mastrelli: For the first time snoeck has managed

To unlock a strontium signal from an ancient cremated bone.

The results of the analysis are shocking.

One third of the people buried at stonehenge

Were not from the local area, or anywhere near.

Instead, they had spent their lives

More than 100 miles away,

Albeit in a part of britain with deep ties to stonehenge.

Snoeck: We've analyzed 25 cremated individuals

From stonehenge

And what we've seen from the results

Is actually a large proportion does not originate

From the stonehenge area but somewhere else in britain,

And the chemical signature that we have measured

On these individuals, actually,

For some of them, it matches west wales.

Mastrelli: These remains belong to the people who came

From the same part of britain as the first stones

To arrive at stonehenge, the blue stones.

Mike parker pearson is convinced it's no coincidence.

He has been examining one of the pits situated

Around the edge of the circle

Where the cremated remains were originally buried.

It's called aubrey hole 7.

He thinks its contents reveal a connection

Between the bones and the blue stones.

Pearson: In the bottom of aubrey hole 7,

The chalk had been crushed to powder.

It'd had a very heavy weight on top of it

And the dimensions of these holes are exactly the same

As those today that hold the blue stones at stonehenge.

Mastrelli: Parker pearson believes

That before they were moved

To their current position in the center,

The welsh blue stones stood

In the aubrey holes where the cremated remains were buried.

If he's right, he may have confirmed

The original purpose of stonehenge.

Pearson: The blue stones, they're almost like tombstones,

Marking the place where human remains would be put.

So, they are absolutely fundamentally associated

With the dead.

Mastrelli: But why here?

Why was this place deemed so sacred

That people would carry their dead

To these standing stones from hundreds of miles away?

(light music)

Mastrelli: Mike parker pearson believes that the landscape

Of salisbury plain was uniquely suited

To the faith and rituals of stone age brits.

Looking at the site from above,

A pair of parallel lines is visible,

Forming an avenue running

Straight towards the stone circle.

This neolithic road was constructed

At the same time as stonehenge and it lines up perfectly

With the sun on the shortest day of the year.

Pearson: If you are walking along the avenue,

You will be looking directly

At where the mid-winter sun set.

Mastrelli: As the worshipers entered

The final stretch of the avenue,

Their path would take them toward their final goal.

A vast monument to an ancient cemetery.

Its stones framing the blazing mid-winter sun

As it set on the year's shortest day.

It's clear that the celebration was timed

To coincide with mid-winter's day.

Each element was constructed to line up with the sun's path.

But parker pearson now believes there was something

That made this landscape sacred

Before a single stone was erected.

Before a single body was buried.

An excavation in the 1950's found a series

Of deep grooves running in a straight line

Within the stonehenge avenue.

And, just like the avenue, they ran in a line pointing

Towards the setting mid-winter sun.

Could these grooves be an even earlier phase of building?

Pearson: The fact that these gullies were running

On a solstice axis led us to assume that they were man made.

So we came and excavated and, to our surprise,

We found that our straight lines

In the ground were not man made at all.

They were natural, they were formed in an ancient ice age.

Mastrelli: The geology confirms that the grooves weren't part

Of the original avenue built 4500 years ago.

They were much older.

Their alignment to the mid -winter sunset was coincidental,

A geological accident, but to the people of the stone age,

These scars in the landscape would have seemed like a sign.

And these gullies may be the ultimate explanation

For stonehenge's existence.

Pryor: I think when people first saw those natural cracks

On the surface, they'd have been in no doubt

That it was indeed a supernatural phenomenon.

I'm in absolutely no doubt that that was the reason

Why stonehenge was eventually located where it was.

Mastrelli: The true history of stonehenge

Is now beginning to take shape.

First, the cremated remains

Of revered ancestors were brought here

To a landscape made sacred by its natural alignment

To the mid-winter sunset.

They were buried in the aubrey holes,

Just inside a circular mount

And their resting places marked with blue stones.

By 2500 bc people from all over the country were converging

On the site to help erect the great stones

And build the monument that still stands 4,500 years later.

Stonehenge had become britain's most prominent sanctuary

Of the dead.

It was the physical and spiritual heart of an island,

United by a ritual fascination with the mid-winter sun.

Pryor: People shared a common world view.

A common explanation for the rising of the sun,

For setting of the sun, the destination of the souls

Of the dead and the meaning of good and evil.

The purpose was to draw people

From different communities across the country.

It was all about uniting communities.

Stonehenge was constructed and was used

By people right across britain.

We say in the roman times all roads led to rome.

I think we can say in neolithic time,

All trackways led to stonehenge.

Mastrelli: Finally, here's one last discovery to chew on.

Those archeologists who just identified the exact quarries

That the bluestones came from,

They think they've found evidence

Of a stone age dress rehearsal.

A temporary monument made from the same bluestones

That would eventually go to stonehenge.