Original subtitles

Tom ward (narrates): A towering, circular structure,

looming over hidden, underground tunnels.

It has a very mysterious, kind of other worldly feel to it,

clearly something top secret was going on here.

A seemingly endless concrete line

stretching through the French countryside.

It looks modern and ancient at the same time,

almost like it is some sort of a ruin from the future.

A building with a decorative exterior,

that was constructed for a macabre purpose.

On the inside it actually had a really sinister purpose,

you would never guess that just by looking at its facade.

And a small facility near London with a secret cold war past.

This is clearly a place someone has built out of fear.

These extraordinary buildings and structures

once helped shape the course of history.

Some led the way in design and construction,

but now they lie abandoned, derelict and crumbling.

Who built them and how, and why were they abandoned?

In the south west of Poland,

close to the border with the Czech Republic,

are the remains of a structure

that's challenging established history.

Seemingly out of nowhere

you see this large, circular structure,

it's almost like aliens have just dropped this from the sky.

What is this thing?

What is it doing here, and you know what?

Something about it tells me there is more than meets the eye.

It is certainly a striking feature of these hills,

but it's not the only decaying structure to be found here.

You see there is lots of other buildings nearby,

and more importantly you see they have dug

and created the tunnels underground,

you wouldn't build a site like this here for convenience,

you build it for secrecy.

So, what was it all for?

And what dark secrets might it be hiding?

A host of extraordinary stories and tales surround this place,

most stem from the later years of world war ii,

when the area was a hive of secret Nazi activity.

The structure has been built

in a remote location miles from any cities.

It's up in the mountains, there is dense woods,

it's out of reach of the allies,

and I think that's the important point.

As the allied bombing of Poland became more intense,

the Nazis moved their weapons

and research facilities to remote locations,

taking care to camouflage the new sites

as they built them.

Sheltered beneath the trees,

this was once a sprawling secret facility,

just one of many in this heavily defended region.

On the ground you would have different defences

consisting of bunkers, machine gun posts, anti-tank posts,

it would be the kind of defences

that would take up probably several thousand men to protect.

In these hills,

this 100ft wide monument stands alone.

Some believe it's simply the remnants of a cooling tower

which was built for a nearby power plant.

But others, such as Igor Witkowski,

think that it was something far more sinister.

And was perhaps even linked to futuristic technology.

In the very centre of this valley

we find such a strange structure visible here,

it's a concrete beam, 32m in diameter,

with very massive columns.

It was built in such a strong way, with strong reinforcement rods,

that it is clear that it was built to withstand really great forces.

Igor believes this concrete circle

was once a key part of the Nazi plan to conquer the world.

I have found a similarity to test rigs

used in the modern times for testing helicopters.

Only this is much larger than one may suspect

that it might have been used

to test some really large flying objects.

The structure is known as the hench.

But what could those strange flying objects have been?

One possible theory is the purpose of this site

is that it was the test facility

for the development of the German's last,

great hope to win the war.

The wunderwaffe or miracle weapon.

One of the most menacing war time developments

was the V2 rocket programme.

Quite a few will hit britain,

and they will cause a lot of devastation.

The V2 rocket was seen as Hitler's last throw of the dice.

The v stood for vengeance,

and it was developed

to avenge the devastating allied air attacks on German cities.

Unlike the v1 rocket,

which was better known by its popular name the doodlebug,

the V2 was a deadly guided ballistic missile

which had a maximum speed of almost 4000 miles per hour.

It arrived at its target without warning.

More than 1400 were fired at britain,

but it was London and the south east of england

that bore the brunt of the V2 terror.

Some 7000 civilians were killed by them.

But some people believe that the Germans were working

on a number of other new projects here at the henge site.

Onto the site we see long, dark, webbed tunnels

that lead nowhere.

Now, we can't see where they go, that's been all blocked off,

but it cannot be a coincidence

they lie just below this weird circular structure above ground.

At first sight, there is little here to suggest

that they were anything other than empty tunnels.

But for those who know where to look,

the story is very different.

We are in one of the tunnels,

connecting the power plant with the underground complex here,

and you have these niches here

where the high water power cables were placed one above the other,

and they give some idea about the size of the entire project

and these cables are the size

comparable with a high voltage power line

that would power a medium sized city.

The suspicion is that even deeper below

the Nazis had commandeered a vast, former mining network.

All these signs of unusual secrecy that we can see in this valley

are only an introduction to the main part of the complex

which is inaccessible today.

Around 1944,

there were reports surfacing of these advanced flying objects

called Foo Fighters who were seen by the allied pilots,

these singular balls of light

that were streaking in the air around the plane,

only faster than the plane.

One theory is that a top-secret technology

called die glocke,

which translates as the bell, was being developed.

The aim was to create a new vertical take-off aircraft

and the henge was to be the final test site.

The theory of the bell goes something like this,

two large spinning disks inside a cylindrical shell

and it was the spinning of these disks,

possibly fuelled by some kind of radioactive material,

that enabled the vertical lift.

Later military tests by the usa

of alternative aircraft were never successful.

But had the Nazis ever cracked it,

in theory they would have been able to develop a machine

capable of out manoeuvring

and out pacing any aircraft in the world.

We know for some time that there is a link

between electro-magnetic and gravity and ground gravity,

but exploiting this new phenomenon

would have been probably the greatest leap in human history,

because it would have been something that would have changed the world.

Whether this was to be used in flying craft

or flying bombs is unclear,

but it does make you wonder

if something extraordinary was in the pipeline,

and had it come to fruition,

might the course of the war been different?

Any hard clues about the work carried out here

are all but gone.

And as the Nazis retreated at the end of the war,

they made sure to cover their tracks,

sometimes in the most brutal fashion.

The scientist working on this project here

might have provided some answers to our questions.

They were killed just in case

to prevent the secret of this place being revealed.

No matter what people say it was used for,

there is no denying the number of buildings,

the security rings, the trenches

and the fact that it took an incredible amount of effort

to create this,

all this leads you to the conclusion

that something quite big must have been going on here.

Today all that remains of the henge site,

are dark, dank tunnels

and this baffling circular structure.

There is still a great mystery associated with this place

that has not been clarified,

but in the very centre of this mystery is the structure.

On the east coast of China,

near the heart of the city of Shanghai,

is a building with a bloody past.

This is such an interesting building,

it's a huge concrete,

multi-storey structure supported by pillars,

but it has all these intricate lattice windows.

From the outside the design of this building

was obviously of real importance to the community,

but on the inside it actually had a really sinister purpose.

A look behind the grand facade

is an unsettling experience.

It was almost like a maze of staircases

and ramps and structures.

Someone really thought hard about the design of this place.

There are sections here

that are completely isolated so whatever went on here,

couldn't see what's going on here.

I don't think anyone would guess in a million years

what it was originally used for.

So, what was the purpose of this mystifying structure?

And to where did this labyrinth of passages lead?

The fact is that the building was once used

as a place of death,

but its dramatic story began before world war ii,

during a time of hope and prosperity for Shanghai.

In the 1930s Shanghai was the place to be,

it was a referred to as the Paris of the east.

Many foreigners came to do business were flooding into the area.

It had a thriving port, it had an industrial centre,

and it was a magnet for businessmen who were looking for new ventures.

Shanghai's increasing financial power

enabled it to become the commercial hub of east Asia,

as banks from all over the world were attracted to the city.

Its success was not confined to finance and commerce,

the arts also began to thrive,

with Chinese music, animation and cinema in particular,

all becoming more popular than ever before.

Today Shanghai skyline towers with the tallest buildings

ever erected outside the United States.

But this low-rise structure

is probably the most intriguing of them all.

As local expert Patrick cranley explains.

It's a very complex building

that reminds a lot of people

of the work of an artist called mc escher,

who used three-dimensional illusion

to create really fascinating works of art.

You almost feel like

you are entering into an escher drawing.

You get disoriented, and then you get fascinated,

you want to figure out how the building works,

and where all these ramps and stairways go.

The convoluted layout offers few clues

as to what the function of this place really was.

Shanghai was the sixth largest city

in the world,

it had more than three million residents,

and was growing quickly.

And the municipal authorities were taking responsibility

for making this a modern city in many ways.

With its colossal size and opulent exterior,

this was clearly a building of vital importance.

But maybe not in the way expected.

The design of this building is very unusual

and really reflects both the creative mind of the designer

and the purpose of the building, which was to slaughter animals.

This building is an abattoir and it's where animals go to die

and where meat is produced for a huge populous.

This is the 1933 slaughterhouse.

But even on the inside, it doesn't look like one,

so how did it work?

The design is very unusual in that it is a square

and then inside a round area where work was done.

Linking the two areas

were a series of Bridges, ramps and staircases.

The ramps were for the animals,

the cattle and the pigs,

and the stairways obviously for the humans.

Different floors were used to slaughter different animals.

The outer area

is where they would keep the animals,

the inner sanctum, that was for the killing.

The building had just one sole purpose...

Everything in it was designed to make slaughtering animals

quicker, easier and more efficient.

If you think about the slaughterhouse,

the smell was probably very, very strong,

so the windows allowed lots of air to pass through.

What was really fascinating was the attention to detail,

so things like rough surfaces of floors

to allow animals to walk

or hollowed out walls for temperature control.

But it wasn't just about keeping the place

light and breezy,

it was designed to deal

with the grim realities of an abattoir.

So, these pipes,

and this trough and the drains are all part of a system of hygiene,

if you drain the blood and other fluids

from the slaughtering of the animals.

These were all features that were thought about specifically

with the function of the building in mind.

The 1933 slaughterhouse ran like clockwork.

Animals were brought up ramps to their designated floor,

and then kept in the large halls,

after which they were led across the Bridges

to the slaughter hall, and into a cage.

The animal was killed by a bolt to the head,

and then the cage was tilted

so it would slide down naturally to the floor

where the butchers would process the meat.

The carcasses were then hung

before being transferred into the chilling rooms.

It was a finally tuned killing machine,

which dispatched thousands of animals every day.

It was almost like a reverse manufacturing process,

so rather than assembling things it was designed to dissemble,

it's such a sinister function of a space,

but in terms of efficiency, it's brilliant.

But although the entire process was ruthless in its efficiency,

there were ever present dangers.

Well since a large number of cattle

were being processed through the facility,

it was important to be able to provide

safe zones for the workers

in case there was a large panic amongst the cattle.

So, the angular nature of these ramps

would prevent a large stampede

and allow refuge zones for the workers.

While that danger could be foreseen,

there were others that couldn't.

A few years after the building was built,

Shanghai dramatically changed.

In 1941, Japanese forces invaded the city...

And this place of death

became the scene of a different kind of killing.

So, this is a cement block house

that was used during world war ii,

to protect the canal that brought some of the animals

and other materials to this area.

So, there would be machine guns placed inside

and they would be protecting both sides of the canal.

Despite years of Japanese occupation,

and the uncertainties of war,

when the fighting stopped and the Japanese left,

the slaughterhouse had survived practically unscathed.

In an occupied city during war time,

the future of this building was uncertain.

But because it was such a well-designed building,

after the war it continued to function as it was designed,

for decades.

The slaughterhouse stopped operating in the 1960s,

but it remained in use as a cold storage facility

and then a medicine factory up until 2002.

It was born in Shanghai's boom years during the '30s,

it sent millions of animals to their deaths

and somehow survived the hell of war.

And even today,

the slaughterhouse remains an extraordinary looking building.

It could have been just an afterthought,

without any aesthetic appeal,

but the designer used his creativity to make something very beautiful.

But its purpose was rather macabre, that is to slaughter animals.

And hopefully it can remain around for a long time

as a reminder of the historical 1930s Shanghai,

as well as a great example of art deco architecture.

Near the small town of chevilly in France,

just 60 miles south of Paris,

there stands a battered concrete platform

which stretches out far across the fields.

When you see this rising out of the countryside,

it looked modern and ancient at the same time,

almost like it is some sort of a ruin from the future.

It's this random structure

that looks like it's something industrial,

sitting in the middle of the countryside

and it just goes on for miles and miles.

But the line isn't complete.

It makes absolutely no sense,

there are three separate sections,

and yet they don't start or end in any particular place.

When you get closer to it,

you see bits of concrete crumbling off it,

and then there is this strange Ridge that runs through the centre of it.

It seems almost blade runner-esque,

but yet it's in the middle of nowhere and clearly does nothing.

So, what was it built for,

and where was it supposed to lead?

Abandoned for decades,

the history of this structure is surrounded by conspiracy theories

and rumours of sabotage.

But today, it still has its admirers.

The structure doesn't look like much now,

but in its day it was the scene of a revolutionary project

that was way ahead of its time.

It was once a continuous track, more than 100 miles in length.

It was an extraordinary project

and it has been a huge inspiration for us.

Today, we want to use the engineering of that time

along with today's technology

to create our own transport revolution.

But if it was intended for use in transportation,

then what kind?

The answer lies in a period

of astonishing technological advances.

The '60s was an incredible period

for the burgeoning of technology,

people were looking to the future in all sorts of ways.

There was the space race, concorde, science blossomed.

While many engineers were looking to the skies,

with this design the ambitions were closer to the ground.

The project was to reinvent rail travel,

to replace the train with something much sleeker, much faster.

You would expect it to just be parallel tracks,

but what makes it really unusual is this Ridge that runs along it,

which kinds of suggests

that there was some kind of innovation involved,

some new thinking.

The remnants of that adventurous new technology

can be found in a nearby warehouse.

It's a strange, futuristic looking vehicle

that was intended to slot onto that concrete Ridge.

This was to be a key step forward in a new way to travel,

this is the aerotrain test track.

An experimental aerotrain

that set a world speed record for trains

hitting 233 miles an hour.

The aerotrain was an incredibly ambitious project.

The idea was a train

that would be powered by a jet engine strapped to it.

It ran on a cushion of air instead of wheels.

You would pump air under the body of the train,

and it would lift the train off of the concrete track.

Essentially the vehicles were flying, hovering,

all you need is a few millimetres of distance

between the concrete structure and the vehicle.

That allowed very, very low friction travel,

theoretically very high speeds.

The idea was the brainchild of engineer Jean bertin,

his first protype proved the theory worked,

and by 1967,

he had built a version capable of a speed of 214 miles per hour.

Initial testing was extremely encouraging,

but what they knew they really needed to do

was scale it up to the size of a passenger train.

But that wasn't the only issue.

Aerotrain had another problem to overcome.

The bigger problem was

there was another project in the pipeline,

the tgv high speed train,

that in many ways was more practical than the aerotrain.

The state-owned tgv was a serious rival.

The pressure was on for Jean bertin

to come up with something really special.

That was the aerotrain 180.

Former pilot, Daniel ermisse,

recalls the experience of taking the latest aerotrain out for a spin.

As the pilot I entered the offices here

to meet the test engineer,

who would then say to me, "this is the plan for today."

It was always such a joy,

just after we started the engine the atmosphere was pure excitement,

because we all knew we were about to travel extremely fast

and in absolute comfort.

Capable of carrying 80 passengers

and reaching speeds of more than 250 miles per hour,

it looked like the winning ticket.

The advantage is the aerotrain

weighed only 20 tonnes,

if we compare that to the tgv that weighs 400 tonnes,

you see it accelerates very quickly.

This place brings back memories.

I can still see myself on the track in the aerotrain.

When the French government

threw its weight behind the aerotrain,

it looked set to be the future of high-speed travel,

not only in France, but around the world.

But seeing the few remaining tracks today,

something clearly went dramatically wrong.

It's very innovative, it's very elegant and cool looking,

and yet it's also impractical in certain ways.

You have to ask yourself the question,

are wheels really such a big problem?

Ultimately tgv won the race.

Then aerotrain suffered a great personal tragedy.

The sudden end was a disaster for us,

but it was an absolutely catastrophe for Jean bertin.

He began to suffer as soon as he knew the aerotrain was over.

We saw this man wither away,

and unfortunately he died a year later in 1975.

But some believe that it wasn't simply the government

trying to save the state-owned network,

other forces may have been at work.

Why was it stopped?

Because somebody wanted it stopped.

Scientifically it was proving to be a brand-new frontier

in the way we would travel,

and then in a few years

that just completely collapsed.

Suspicions that aerotrain had been the victim of a conspiracy

were inflamed by a strange disaster in 1992.

It came after the local mayor announced

that the aerotrain hangar would reopen for tourists.

It was all very exciting, but then within a few days,

the hangar that was actually housing the train, burnt down.

What was very mysterious

was this was actually the second fire to have occurred.

There was someone somewhere

who really wanted this over for good,

so the aerotrain was set on fire.

Coincidence?

While the aerotrain project seemed fated never to succeed,

the track may have found a new lease of life,

with a more modern project called space train.

Space train is a shuttle project.

A shuttle which is propelled to around 500km per hour

on a cushion of air.

The concept of aerotrain was very inspiring

for our project space train.

This structure is in a very good condition,

we would like to re-use it to do our first test.

Projects that fail, that don't come to fruition,

still add to our human knowledge, they add technological skill,

they bring new materials, new ideas,

that might ultimately affect other fields,

or other forms of transportation.

In a wooded area, 20 miles north east of London,

lies an inconspicuous building

which was constructed far away from prying eyes.

The first impressions of this site

really are nothing surprising,

there is a bit of an innocuous tower,

you have got a small house nearby,

but other than that, nothing really untoward.

Even though it is well cared for,

you can just tell that no one has ever called this place home.

This small building in fact harbours a big secret.

Once you go through this unobtrusive front entrance,

now you realise

that you are in a very large kind of operation.

You go into this long underground tunnel

that leads into a big underground labyrinth.

You can tell

that somebody wanted to come underground

and hide something very valuable

from something very terrible.

This is clearly a place someone has built out of fear.

So, what was it that made people build this here,

deep underground near the UK's capital city?

The reasons can be found by looking back to the tense

early years of the cold war,

when the world had just entered the nuclear age.

1949 Joseph Stalin,

who was one of the most ruthless brutal dictators of history,

explodes an atomic bomb.

This takes the west by surprise.

And this changes the entire game.

The atomic bombs dropped by the allies

on Hiroshima and Nagasaki in Japan in 1945,

had finally ended the war in the pacific.

They also increased Stalin's determination

to accelerate the Soviet nuclear programme,

something he did through ruthless intelligence gathering,

and by using captured German scientists

to develop nuclear weapons.

The first successful nuclear test came in August 1949,

at a secret site in Kazakhstan.

The bomb was code named 'first lightning'

and it was based on the us fat man, plutonium bomb.

President Truman has announced

we must now alert the whole world to the peril

that this event brings into being.

With fear of a nuclear war growing throughout the world,

facilities like this one sprung up across britain.

But they weren't simply to provide shelter.

During the world war ii,

britain had a network of radar stations

to warn of Nazi attack,

but once Soviet nuclear attack became a threat,

it was a hasty effort to build new ones.

Early warning becomes a top priority

during the cold war.

That signal means to stop whatever you are doing

and get to the nearest safe place fast.

Those few minutes of early warning

might make the difference between an effective counter strike,

effective survival of your forces or some of your forces,

and your national destruction.

Built under a cloak of secrecy,

a new radar system named rota

was established in a network of operation centres

around the country,

including this one, the kelvedon hatch,

secret nuclear bunker.

During the nuclear weapons testing

and in the late 1940s early 1950s,

they realised that everything above ground,

even the small nuclear weapon would just devastate everything,

it is all gone.

However, people could survive if they are underground.

The location itself was somewhat strategic

because there was an raf base nearby,

but also the nature of the rock was important,

because instead of being on soft material

like the London Clay,

this was actually under much harder bedrock.

Covered by more than 13ft of top soil,

the outer layer of the bunker has a Faraday cage

to protect it from stray radio signals.

Inside that is a brick skin,

a 10ft thick concrete wall and three operation floors.

A 360ft tunnel leads out to the entrance,

which masquerades as a small countryside bungalow.

This was a colossal construction

27,000 square feet of area,

completely hidden

and there is about 40,000 tonnes of concrete

that was used to construct the whole thing,

a real engineering marvel.

Everyone new in the '50s

that there were Russian spies everywhere,

and that meant

that it was impossible to keep it a secret,

that there were command bunkers all over the country,

but nobody knew exactly where those bunkers were located.

The site is now owned by farmer, Mike parish.

Mike has become an expert on what went on here,

and particularly on the bunkers imminent attack protocol.

We have now got the blast doors here,

which once they are shut,

well everybody will be in here for at three least months.

The bunker was able to support up to 600 people,

once they were locked inside it was these machines

that would keep the deadly radiation out.

The air would normally flow into this fan here,

which would just pump it straight into the bunker.

But if it had become contaminated,

then they would switch that one off and switch the one over there on

which would in theory filter all the nasty things out

before it actually got into the bunker itself.

So, actually, this is what's keeping us all alive.

But while the completed bunker functioned as planned,

the new rota network soon encountered a problem.

Built in less than a year, very, very quick,

but interestingly as well, in such a short time,

the way that the radars were changing,

it became fairly redundant quite quickly.

Within a few years there was no longer a need

for the rota control centres.

But with its proximity to London,

and the country's central government,

the site would soon have another important role to play

in the event of a nuclear attack.

All major powers during the cold war

developed large underground bunkers,

facilities that were survivable in case of nuclear attack,

and that was to preserve and protect the government.

If everything goes wrong, here is a way

at least that they can maintain some kind of control,

even in the devastated country afterward.

By the mid-1980s,

britain had established a new network

of regional government headquarters,

many of which utilised the former rota bunkers.

The British government

was going to briefly disintegrate

when a nuclear attack happened,

and all of the cabinet members

would be assigned a different region of the country,

where they would go and as a minister of the crown,

would be the most senior person for miles around.

In this worst-case scenario,

this facility is near London,

it would have protected several hundred of the key personnel

and enabled them to live for weeks.

With telecommunications

linking kelvedon to other regional headquarters

and housing a BBC broadcasting suite to speak to those on the outside,

the officer in charge would have played a vital role

in coordinating the nation's response.

But the first step was to convince the public

that there was a real chance of survival.

It was important to government

not to let people know

just how bad the effects of nuclear war,

thermal nuclear war would be.

They were afraid that if people really knew what would happen,

they would lose hope.

So, governments all around the world,

began to issue advice

about what to do in the event of a nuclear attack.

But had the bombs ever been dropped,

it would have been in rooms like this

that the real fight for survival would have played out.

They would be able to plot it on these cold perspex here,

the red ones were ground bursts,

they produced a lot of radiation

because they picked the dirt up

and that is what the threat was, is radiation is carried on dust.

There would be people the other side there

who would be able to write backwards,

describing where the radiation is flowing,

so all the time that information was fed upstairs

so that they would be able to deploy buses

and coaches to move the population out of the way of the radiation

if that was indeed possible.

If the worst had happened,

the fate of the people and the country

would have been in the hands of those working here.

I suspect they would have been very professional

and they would have got on with the job,

but I know if I was down here

and I knew my family was at great risk

and the whole world was about to fall apart,

I, my mind wouldn't be 100% on crayoning

in which way the wind was blowing.

Although it was primed and ready for action for decades,

the site was, thankfully, never needed.

When the threat level dropped, the bunker was decommissioned.

With britain never having suffered a nuclear attack,

today, kelvedon might appear to be the very embodiment

of cold war paranoia.

But was it?

I don't believe in using the term paranoia

when we are talking about the cold war,

because paranoia indicates an irrational fear,

and when you are talking about the Soviet union

and Joseph Stalin,

you are talking about completely sensible, rational fears.

Now they lie abandoned,

but once they were at the cutting edge of engineering.

There are echoes from history in these decaying structures,

they remind us of terror and war,

but also of great innovation and human endeavour.

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