Original subtitles

A brutal Soviet fortress overlooking the baltic sea.

You could expect to lose yourself in those cold, horrible walls.

An extensive bunker system built

in the extreme altitude of the French alps.

Why would anyone build something like this so high up in the mountains?

A deserted jungle highway that leads nowhere.

If I was wandering around the rainforests in Brazil,

I think the very last thing I would expect to see

is a massive piece of concrete.

And a little-known complex at the heart of the American

immigration story.

To say that this place is atmospheric

would be an understatement.

It's really creepy.

Once, they were some of the most

advanced structures and facilities on the planet,

at the cutting edge of design and construction.

Today, they stand abandoned, contaminated and sometimes deadly.

But who built them and how?

And why were they abandoned?

Near the southeast coast of Brazil, amongst the mountainous peaks

of the serra do mar, is an imposing structure.

Emerging out of the morning mist and reaching across the rainforest

is what appears to be a huge section of highway.

It's misty. There is clouds rolling in

and, when you focus, all of a sudden you see this huge concrete structure

and it's just growing up out of the jungle and then disappears.

It's as though a giant just picked up a huge

concrete piece of lego and dropped it there.

See, if I was wandering around the rainforests in Brazil,

I think the very last thing I would expect to see

is a massive piece of concrete.

And forget just a massive piece of concrete but an actual

abandoned piece of flyover. That would be really, really bizarre.

Who built this domineering flyover on the side of a mountain?

And where does it lead?

In the 1950s, the Brazilian government began constructing

a trans-coastal highway.

Known as the br-101 freeway,

it would eventually form Brazil's longest highway,

stretching nearly 3,000 miles north to south.

Yet this segment of the 101 appears to be deep in the jungle,

far from the stunning beaches of Brazil's east coast.

Brazilian engineer Newton Jose cavalieri knows the freeway well.

(Speaks foreign language)

This section was left unbuilt.

But in the 1970s, Brazil's military government invested

heavily in massive infrastructure projects

and plans to bridge this mountainous strip were renewed.

The original plan was to take the freeway over the mountains.

Now, that had all sorts of inherent challenges

so they looked for an alternative.

Through the jungle?

That's gonna be difficult.

But how about over the top of the jungle?

They decided to follow existing dirt roads built by

the state-owned petrobras oil company to maintain their oil pipeline

that ran through the jungle.

In the midst of an economic boom, known as the 'Brazilian miracle',

engineers forged the most direct route possible

with the help of tunnels and viaducts.

And one of the key pieces of this ambitious highway puzzle was this,

the petrobras viaduct.

(Important music)

It would help to bypass over 30 miles of coastal road

that looped around the peninsula.

You can imagine how difficult this was to construct.

First of all, you're in a jungle.

It's inhospitable, it's hot, it's humid, there's trees and insects.

Despite the challenges of building a viaduct that was over 130ft tall

and 1,000ft long in these harsh conditions,

Brazil's military government had good reason for investing

in this jungle highway.

It was linked to their nuclear ambitions.

To advance their nuclear capabilities,

they began building reactors and this section of highway became vital.

(Speaks foreign language)

As Brazil entered the atomic age,

they needed an escape route to the south of Rio de Janeiro,

in case of nuclear disaster.

So the br-101 had to be completed before

the nuclear reactor went online.

Various teams worked along the route on different sections,

some faster than others, but all faced an array

of engineering challenges whilst also in a race against the clock.

So, when you're trying to build quite a complex

road network and that might have tunnels, it might have

flat pieces of road and it also might have these flyovers,

what you want to do really is to do the most complex pieces first.

They're the most expensive.

They're gonna take the longest and they need the most amount

of investment in order to get them built.

So it's a good idea to get the hard bits finished first

and then what you can do later, more easily, is just to join the dots.

So that's the kind of typical way that you would

build something, even though it sounds really counterintuitive.

(Speaks foreign language)

There are a lot of things that can make your life very difficult.

That can start from the ground being quite wet,

having lots of roots of trees there.

You're thinking about,

"how do I bring the material to that location to actually build it?"

How are you gonna get cranes there?

And then if it's hot and humid, to add to that,

that makes things even more difficult.

Despite the precarious working conditions,

jungle humidity does have one engineering benefit.

So, strangely enough, the one thing you don't really need to worry about

is the concrete going off because you've got the humidity

there and actually, having quite a humid environment

means that the concrete cures better and it gains its strength

really nicely and uniformly across its whole body.

However, this supposedly key component

of the freeway system would never fulfil its purpose.

With the nuclear plant suffering construction delays

and defects well into the 1980s,

the Brazilian economy was slowing, exacerbated by a global oil crisis.

With funds dwindling, the freeway was scrapped

and left standing where it remains today.

Demolishing a viaduct can actually be more expensive

than the construction cost itself and so, many times,

it's easier to leave a structure like that in place.

The petrobras viaduct is a sad reflection of poor planning

at a time when Brazil's economic miracle came to a shuddering halt,

replaced by turmoil and crisis.

Never linking up with the angra nuclear power plant,

it was simply left to be consumed by the jungle.

Today, this concrete freeway is rooted to the rainforest floor

and is rarely visited.

The petrobras viaduct just imposed itself on this jungle.

So I think it's somewhat ironic but completely fitting

that nature is now consuming it back from whence it came.

And I think that's a fitting end to something that probably shouldn't

have been there in the first place.

In Europe, on the coast of Estonia's capital city,

Tallinn, is a structure with a very dark past.

Spread over 180,000 square feet,

this ominous three-storey fortress,

battered and salt - sprayed by the sea,

once housed thousands of people.

The really peculiar thing

is this triangular-shape masonic-looking sort of structure

that protrudes from the centre of it and it just defies explanation.

Then when you get close up to the site, you realise, "hang on!

What's all this barbed wire about?"

Inside the building,

miles of winding corridors pass hundreds of empty, rotting cells.

You walk along the halls and you're instantly struck by

how cold and stark this place is.

It was never constructed to give whoever it was that inhabited it

any sense of comfort.

Why was this stark facility constructed in Tallinn?

And who was imprisoned here?

(Serious music)

(Gunfire)

Russia's long domination of Estonia stretches back to 1700

and the great northern war.

Over the centuries, Estonia, on the edge of the baltic sea,

provided an excellent strategic location for Russia's military

and intelligence services

and provided their Navy with access to baltic waters,

close to its European enemies.

After Joseph Stalin's rise to power, the ussr increasingly expected

the baltic states to bow down to the communist regime.

Opposition was often brutally crushed.

(People screaming)

Ussr was this huge controlling monolith.

There was no opposition allowed.

If you were a leader of some of those baltic states like Estonia,

there was only one thing that was gonna happen to you.

You would be locked away in prison,

pretty much the key would be thrown away.

This former Russian naval sea fortress was built in 1840.

But in 1919, it was turned into what would become

one of the most dangerous institutions in the communist world.

Patarei prison.

Patarei prison was a branch of the kgb in Moscow.

It was the hell of the most ruthless intelligence agency

in the world.

Patarei gained a fearsome reputation as a place of terror.

Anyone who resisted Russian expansion would likely end up here.

Curator Martin andreller

is an expert on what life was like for prisoners inside these walls.

This was the place and synonym

for the communist terror that was made in Estonia.

How many prisoners the Soviets kept here, we don't know.

But in the cells, there were around 80 persons per one cell.

You would have one toilet and cold water by design.

You'd have a blanket, that's it.

The whole intent was to dehumanise you, to make you feel

as though you're not worth anything better than this.

It was a nasty place.

Former prime ministers,

politicians, diplomats, they were also held here in patarei.

And all the routes towards Siberia or towards the graves

started from this building.

Patarei was used as a staging post, a place where thousands of prisoners

and forced labourers would stay

whilst en route to the gulags in Siberia thousands of miles away.

The Soviets were willing to deport thousands and thousands

of Estonians to Siberia just for being Estonian.

And the conditions in patarei were severe.

(Serious music)

Patarei was a way of bringing the frozen hell of Siberia,

the ruthless exploitation of Moscow,

right into the centre of Tallinn.

Yet this inhumane Soviet treatment

of prisoners would ultimately contribute to its downfall.

Methods of physical and psychological torture employed

at the prison and elsewhere

led to a deep-seated hatred amongst Estonians for all things Russian.

And it ignited strong resistance against their old enemy

from a group called the forest brothers.

We first find the phrase, 'forest brothers',

in the baltic region around the time of the Russian revolution,

around 1905, and supposedly it comes from school teachers

and peasants taking refuge in the forest,

hiding against the occupation by Russia.

It turns into a real political movement

where partisans of all the baltic states are

willing to fight for their lives against the Russian occupation.

Following the Soviet invasion during world war ii, as many as 50,000

forest brothers across Estonia, Latvia and Lithuania took up arms

and employed guerrilla tactics to resist and disrupt Soviet forces.

You don't even have to take to the forest

with a gun in your hand to be sent off to Siberia.

So when they get genuine insurgence into their hands,

the Soviet security services are horrible to them.

They're cruel, they're ruthless and they try their best -

the kgb does - to make it impossible to continue to oppose Soviet rule.

In patarei prison, there have been

numbers and numbers of famous prisoners.

One of the leaders of the Estonian partisan movement

against the Soviet regime, 'ants the terrible',

as it was his nickname,

was also kept here in patarei before his execution

in the start of 1950s by the Soviets.

Numerous members of the forest brothers partisan movement

ended up here, condemned to a life of a solitary confinement.

The Soviets were excellent at manipulating

uncertainty in order to divorce prisoners from reality.

They took away your sense of time

by taking away natural light.

They took away your sense of biological time

by feeding you at irregular intervals.

You could expect to lose yourself in those cold, horrible walls.

During the cold war, there's a real interest in any groups who were

resisting that Soviet rule, and the forest brothers were

secretly getting support from both MI6 and the CIA.

Each of which had a vested interest in the forest brothers' success

'cause they wanted to see

Russia and communism stopped in its tracks.

But the design of the prison meant that only three escape attempts

were ever made from patarei and all ended in failure.

Alongside the presence of the much-feared kgb,

this was one of the most secure sites in Europe.

Of course, it was very hard to get out.

The walls itself is based around a naval fortress.

They were very thick, over 2m.

And of course, the systems of the internal security,

all the doors and so on, so it was basically not possible to do

that if you didn't have the inside help from the prison guards.

Otherwise, you couldn't get out.

The last execution at patarei took place in 1991,

the same year that the Soviet union collapsed.

The Russians may have left, but patarei continued

to function as a prison until 2002.

This building, soaked in tragedy, lies derelict and abandoned.

A dark reminder of a haunted past.

You can go and really see what that Soviet oppression

was all about for anyone who was imprisoned there.

It's almost an opportunity today to still look behind the iron curtain.

Its future, however, looks brighter.

Plans are afoot to regenerate the complex, potentially as a museum

dedicated to the memory of those who suffered inside these walls.

Off the coast of New York City, at the mouth of the Hudson river,

is a gateway to america.

But not the one you might expect.

In the shadow of lady Liberty lies a 28-acre manmade landmass...

Scattered with 22 red brick buildings that contain

a deadly past.

To say that this place is atmospheric would be an understatement.

It's really creepy.

There's vines growing on the walls, there's bars on the windows.

All you can hear is dead silence

and the occasional, sort of, seabird crying in the distance.

It's no wonder it brings about

images of horror movies and experiments kind of gone wrong.

The collection of decaying buildings that you see

looks almost military, as if it was to house a Garrison

of troops ready to defend the coast.

Dappled light and sea-air stream through the large windows

of this dilapidated complex.

Yet it sheds little light on its original purpose.

If you were to find yourself walking down the corridors

of this place, you would ask yourself, "what's going on?"

These huge, iron-clad doors with these sealed tight sort of locks.

"Is this a prison? What is this place?"

Why was it necessary to create a new landmass?

And what was the purpose of this sprawling complex?

In 1892, Ellis island opened its first immigration station.

700 immigrants passed through its doors on the first day alone,

as people came from all corners of the globe.

In total, the 12 million immigrants who would pass through New York

were taken to Ellis island to clear immigration checks.

They brought different cultures, languages and much-needed labour.

But that wasn't all they were bringing with them.

America had opened its doors

and that sounds great but the dark side, the flip side,

the concern that no-one really probably thought through

is that you're welcoming disease from all over the rest of the world.

There were no shots, there were no antibiotics you could

give people as they walked through the door.

You had no idea what they were bringing with them

and this created the need for a hospital.

This was Ellis island immigration hospital,

america's first line of defence against disease,

and one of the largest public health hospitals in us history.

Its job was to stop a dangerous outbreak of disease from spreading

across the country.

People have this image of immigrants coming through

Ellis island into the us in this kind of hellish, scary

facility, Ellis island. And it probably was

somewhat scary for people. But in some ways,

it was also very enlightened and very modern.

An absolute state-of-the-art hospital that had huge capacity,

highly trained staff.

John mcinnes of save Ellis island

works to preserve this historic facility.

This hospital opened up and employed the most modern

medical practices that existed in its day.

It was purposely designed to protect the people who worked here,

the people of the United States and the other immigrants.

This cutting-edge medical facility was so vast it required

its very own purpose-built island, separate to the immigration centre.

Back in the day, when you arrived at Ellis island,

you were greeted with a security check and a health check.

It forced the health community to grow its expertise,

to test for things, to learn, to become more proficient

and it was really the Genesis of the American healthcare industry.

In 1898, construction began on island number two,

which would increase the total mass to over 15 acres.

But how do you build an island in a body of water?

We're taking inspiration from the ancient Roman engineers.

So, what they used to do, which was quite cunning,

is to create two rings made out of timber logs,

and then pack the little space between these two rings with Clay,

pump the water out from the middle,

and then you've got a dry space in which to work.

Labourers filled the watertight framework of the island with rubble

from the newly excavated New York subway.

On the new island base, six dedicated hospital structures were built

at a cost of over $23 million in today's money.

By 1901, the hospital was processing huge numbers of immigrants.

Most of us get nervous today going through airport security.

But that's nothing compared to

the anxiety that immigrants felt as they arrived at Ellis island.

We've been on planes for hours.

They've been on boats for weeks in dire conditions

and they don't speak the language.

You can imagine the anxiety, the confusion

and the tension on both sides.

In 1907, over a million immigrants passed through Ellis island.

And the medical complex was overwhelmed.

To isolate and control contagious diseases, they built a third island,

200ft across the water.

The hospital buildings were located on separate islands for good reason.

It was in response to the prevailing germ theory,

the belief that germs could not travel across a body of water.

One of the reasons Ellis island was built

on an island in the first place is because it isolated

the complex from the rest of the north American population.

If there was some kind of epidemic or disease, it could be held

on that island and wouldn't immediately be spreading

through the rest of the population.

Consisting of 17 separate buildings, all dedicated to specific illnesses,

the contagious disease hospital could seal off

each individual section, preventing the spread of deadly infection.

You could be brought to a ward like this. This large, open room.

It's all gonna be likely men, just like you. You're gonna be here.

Beds are gonna be between each of the windows, surrounding the area.

Now, this room is actually a design theory

of Florence nightingale's from 1860.

She thought there was something in the air called 'bad air miasma'.

So she had this theory of getting it out of the room.

And what you see is actually engineers putting it at work.

Three sides of fresh air and sunlight coming through.

These large windows, they're gonna be open

about 18 inches throughout the year, to allow the bad air out.

And then she has something unique in design,

this coving that you'll see around the ceilings.

That's gonna facilitate the flow of air,

allow the air to travel up the walls, collect the bad air out,

come out the other side, go out the window the other side of the room.

An advanced theory in 1860.

This was the age of tuberculosis and cholera

so disease control was Paramount.

The onsite industrial laundry processed

3,000 towels and sheets daily.

There was even a giant steel chamber, called an autoclave,

that used high-pressure steam to disinfect mattresses.

Doctors and nurses went to great lengths

to prevent cross-contamination.

And the room's gonna be locked

and people are gonna be here for about three weeks

while they're being treated for their infectious disease.

With few antibiotics available, it was simply a case of waiting to see

if the patients got better or worse.

It must have been a scary process.

You were threatened with being sent back home if you didn't recover.

The good news is, the vast majority of them did.

Only about 1% of the passengers were returned

to their home countries because of illness.

Ultimately, Ellis island's medical facility was a success.

But modern technology,

along with advancements in medicine, ironically outstripped

the island's once high-tech facilities

and it was forced to close down.

After the hospital closes its doors for immigrants,

the island continues to be used by the FBI, which is quite interesting.

And then as a prisoner of war facility.

So it had some functional use after it closed down

as an immigration hospital.

But ultimately, it would close its doors for good.

In 1954, Ellis island and its hospital were abandoned.

Once bursting at the seams, this medical institution lay empty

and derelict.

But today, thanks to the save Ellis island foundation,

the hospital is being restored

and has reopened for so-called hard-hat tours.

Immigration centre is a popular tourist attraction.

They come in droves. But what they don't see

is the hospital right nearby.

And the hospital, you know, it should be thought of

as every bit as important as the immigration centre

'cause this is where the legacy of American healthcare can

really be celebrated.

Over 6,000ft up in the French alps

are a series of deserted and mysterious structures.

What race of beings built this vast

encampment, so much of it underground?

It's like something out of tolkien,

you know, something the dwarves would have built.

A maze of dark, desolate corridors

leads into the deepest recesses of these mountain peaks.

Why would anyone build

something like this so high up in the mountains?

Why build these bizarre alpine structures in this barren location,

only to leave them abandoned?

In the 1930s, Nazi Germany was threatening expansionist policies.

With world war I fresh in the memory,

France set about protecting their borders from the old enemy.

They built a set of defensive fortifications,

now infamous as the maginot line.

It was a labyrinth of fortification above and below ground,

considered at the time the ultimate in military defence.

(Explosion)

The idea of the maginot line is, it's not just one wall or one line.

It's a defence in depth.

So you have anti-tank barricades, sections of barbed wire,

you have lookouts.

It's not like the great wall of China.

It's more like a system of defences

that's layered over the whole border area.

You should always consider defence in your strategy. It's like boxing.

You don't just punch. You protect yourself, as well as punching.

Their idea was basically, "let's build up all the infrastructure

we need to defend our country.

So if the Germans come, this time we'll be ready."

But Germany was not France's only enemy.

They faced a new threat from another fascist force allied to the Germans.

Benito Mussolini's Italy.

The French are very mistrustful of the Italians in any case.

They have long considered the possibility

that these two great mediterranean nations may get into a war.

Who's going to trust Mussolini?

(Dramatic music)

As tensions with Mussolini's Italy start to escalate in the 1930s,

the French develop further fortifications

along the alpine line,

along France's mountainous border with Italy.

Just four miles from the Italian border,

along the crest of these mountains, is the highest and most impressive

alpine fortress on this line.

(Dramatic music)

It's called ouvrage restefond.

Even a relatively small outpost in this mountainous landscape

could play a vital defensive role.

An alpine fortress could control passes with artillery and make it

difficult or impossible, even under the best summer conditions,

for Mussolini's army to come through the passes into France.

Construction began on ouvrage restefond in 1931.

But miles from anywhere, access and supply proved

a logistical nightmare.

Forts are dug and drilled into the ground going right down,

in many cases right down into bedrock.

French engineers had tremendous difficulty with the logistics

of moving heavy equipment and concrete up into the alps.

Despite these challenges,

they were built to withstand heavy bombardment.

They're made of reinforced concrete. Reinforced concrete means

it's concrete poured over a lattice of steel bars.

So those things could take incredible punishment

without caving in.

And in these brutal high-altitude conditions,

how would they effectively man and defend this position,

isolated for extended periods of time?

These fortresses had to be self-contained.

They needed their own power, water supply.

They had to have everything they needed to sustain

hundreds or even as many as 1,000 troops

through brutal alpine winters and periods of minimal supply.

So food, hospitals, bunk rooms, everything you would need

but all underground, all protected from bombing, from artillery.

The ventilation systems was able to vent, not only to protect

the occupants from gas attack, but also from the diesel exhaust

from their own generators and from the gasses coming out

of their own artillery pieces.

France's worst fears were realised

in June 1940 when Nazi Germany and fascist Italy joined forces.

(Cheering)

They formed what became known as the pact of steel.

The French troops were marched into their modern caves to wait

for the Nazi blitz to smash itself against the maginot line.

(Explosions)

With this Nazi blitz now on the verge

of overwhelming Western Europe, France was forced to divert military

resources to the battlefronts, away from this alpine region,

leaving it largely undefended and manned by inexperienced troops.

The maginot line is designed to efficiently use poorly trained

conscripts who only have a short period of service,

by putting them into positions where all they have to do

is perform one simple task.

And all of those soldiers, augmented by the technology

of the maginot line itself, are able to defend France.

Yet it's clear today that the network of bunkers here

in France's highest maginot fortress was never fully completed.

While the maginot line is built, well over a decade in construction,

parts are still being built, of course, as the war breaks out.

Could this partially complete line of defences withstand

the German advance?

And a potentially imminent attack from Italy?

On 10 June, 1940, Mussolini, looking to cash in

on their imminent defeat to Germany, invaded France.

The Italian army had a lot of alpini,

alpine soldiers, who were trained in exactly

the kind of warfare you need to get into France through the mountains.

The passes through these otherwise impregnable mountains

were the main route into France for the invading Italian army.

So the French defenders knew exactly where to aim their guns.

You can't underestimate how powerful even a small fortress can be

in denying alpine roads to a modern mechanised army.

Everything had to be engineered

so that they could have overlapping fire.

They could aim their guns from several different angles at once,

onto an area where the enemy might come.

The gaping voids in these crumbling fortifications

once held an array of machine guns, mortars and heavy artillery.

Now the only reminders

of its armaments are their protective dome shells.

The domes that cover each of the machine gun emplacements

are thick steel.

Even German 88mm guns had

tremendous difficulty penetrating

the steel domes on top of those maginot line fortifications.

These alpine fortresses succeeded in halting the Italian onslaught.

The fortifications held out quite nicely.

The invading Italians will suffer a genuine humiliation.

Relative handful of French forces will throw back

the overwhelming forces of Mussolini,

largely due to these very effective fortifications.

But French success was short-lived.

Their spectacular victory against the Italians was all in vain.

After just 46 days of fighting,

the German war machine forced France to surrender on the 25 June, 1940.

Germany's Italian allies could now flow through

the partially constructed alpine defences.

If the French had managed to build

restefond as powerfully as it was designed,

it could very well have stopped

a lot of Italian combat power getting into France.

No longer useful to the French and never repurposed by invading

fascist forces, ouvrage restefond was left deserted in the mountains.

Today, the remains of these defensive fortifications

carved into the mountainside serve as a monument to this global conflict.

Ouvrage restefond is a testament

to French engineering skill and military technology.

Creating something that has the staying power

to remain there for decades, and it will remain there for centuries,

is very special. It's a kind of engineering magic.

(Serious music)

Now abandoned, they were once on the cutting edge

of human engineering.

Within these decaying structures are the echoes of history.

They speak of war and terror

but also of exploration and human endeavour.

Captioned by ai-media ai-media. TV