Original subtitles

(Dramatic music)

Narrator: An intriguing ruin carved in to a sardinian cliff face.

It's not only the fact this tunnel sort of leads out to sea

but it comes out half way up a cliff.

An eerie facility in the usa with a gothic look and feel.

Those gargoyles are very strange.

Almost like they're guarding something

or perhaps warning people about what's inside.

A top secret building in Japan that may have called a nation to war.

The units stationed there burned all the radio transmissions,

all the receipts, everything else that was there

so we have no paper record

of what actually went in and out of that place.

And an extraordinary underground labyrinth of tunnels

in southern Ukraine.

So, increasingly disorientated underground

these Russian secret police begin to hunt each other.

(Dramatic music)

Decaying relics...

..Ruins of lost worlds.

Sights haunted by the past.

Their secrets waiting to be revealed.

On the outskirts of louisville, Kentucky

perched on the top of a hill

lies the battered shell of a huge imposing building.

It's not the kind of place you'd stumble across by accident,

it's pretty secluded.

To get to the place

you have to take this long winding drive

that snakes up the hill.

At first sight there seems to be more questions than answers.

You can't really tell

if this is the front or the back of the building.

How do you get in? It's a bit disorientating.

This rambling structure seems to go on forever in every direction.

While ominous looking creatures gaze down from above

inside there's an eerie and confused picture.

We have to ask why are these abandoned?

What terrible thing happened here that makes people want to stay away?

And how is it linked to a modern day global pandemic?

A three-storey solarium dominates it's southern face,

could that unlock the mystery of this buildings original purpose?

There would have been a bed

pulled out in front of every single open doorway.

All the way down and around this thing,

across the whole back.

Dale Clark grew up just five miles away

and has been showing people around here

for the last 18 years.

Then there were usually smaller children's beds

shoved up against the brick wall on the outside.

And there was just a little path

between the foot of the beds over here

and the side of the beds over there.

They spent a good chunk of their time out here.

It must have been a very strange sight

coming up that driveway

and seeing all the people out like that.

But what were they doing out there?

It's not like there's a view of the ocean or the river

or anything like that.

This is waverley hills,

a 180,000 square feet facility

built to house over 500 people.

But here the devil is in the detail.

So, if from the outside

it looks like maybe it could be a fancy hotel or retreat,

the inside has a very different feel to it.

There's not much left behind

but there are odd bits of medical equipment.

This is not just a place of life

here in the hills of Kentucky,

what we're looking at is a place of death.

This is the morgue.

We have no idea why this room is so small.

At the worst cases a body an hour,

this little room's going to fill up very quickly.

That's why there's a maintenance department

down the far end of the building,

that's four times the size of this.

It became the auxiliary morgue during the worst of it.

When you need to have an auxiliary morgue

you're taking a lot of bodies.

Waverley wasn't alone,

the body count was piling up all over the United States

and around the rest of the world.

It hit the us so badly

that they had to form a national committee

to deal with the problem.

A global pandemic of this disease

struck terror in to the hearts of everyone.

The disease was tuberculosis.

Built in 1942 this was more than just a hospital.

You've also got dentists and a barbers and even a gift shop.

Patients are not just here for a few days,

the patients are here long enough

to grow their hair long and get it cut.

They need to function in this place for the rest of their lives.

Children that were born in waverley

had to be taken away from their mothers

immediately after birth,

the risk of contamination was that severe.

And it gives you some sense

of how long people were confined here

if they were having children born here.

The story of a patient called Lois

demonstrates the heart-breaking realities.

She was a mother of two when she got here

and if a patient was doing better

they would allow them to go home on furlough

and then have to come back.

She came back and it didn't go well,

she had conceived a child while she was gone.

To our knowledge the only time Lois ever got to see her son

that was born here

was standing in one of these solarium windows

looking at the road that ran across the back of the building

and somebody held him up.

Patients need to be isolated,

they need to be kept away from cities and towns

where they could cause thousands of infections

and thousands of deaths.

It can survive in the air

and it can attack any organ in your body

but it usually goes for the lungs.

The victorian name for it was consumption

because it consumes your body from the inside.

At one point across america and Europe,

one in seven deaths were down to tb,

one in seven people died of tuberculosis.

Jefferson county, Kentucky

was one of the worst hit places in the country.

Fortunately waverley hills Rose to the occasion.

Waverley is as good as it gets.

Here is a place where you're going to be looked after by the best.

If you're going to try out a new procedure

waverley was where you were going to try it out.

And they were really at the cutting edge of tb treatment.

But in the early 1900s

the best tuberculosis treatments were still experimental

to say the least.

Procedures we talk about most of all in here

are auto-pneumothorax

which is basically where they would let air in to your chest cavity

and manually collapse one of your lungs.

It's very, very painful,

they thought, mistakenly,

that while the lung was collapsed it would rest and heal itself.

Medical science had not yet learned how to deal with this disease

and that the best way to heal

was for the patient to heal himself or herself.

Aside from these procedures

there were only three treatments thought to be effective against tb.

Fresh air, sunshine and nutrition.

This building has areas purpose built for that.

Here along these massive balconies called solariums.

These are the best treatments they had

but as we know from the number of people that were dying here

it wasn't really that effective in the end.

(Piano playing)

There are hospitals today which have a whole separate set of corridors

for moving dead people out of rooms.

The solution here was more direct, a body chute.

It was not originally built to be a body chute,

it was built to bring up building supplies and materials.

All the mechanisms, machines, the track and everything

that was built to bring bricks up,

they just reversed it and took bodies down.

Bottom there was a little building

it was basically storage

so they could either be loaded into hearses,

ambulances, train cars depending where they needed to go.

This is just a grim form of architecture

but totally necessary.

And scrawling's on the walls

serve as a reminder of the risks taken by the staff who worked here.

The employees were the original graffiti artists,

there's a lot of names signed in pencil,

quite a few of them are dated and some of them are very old.

Just to let themselves know that they're still alive,

that you know they came and did a horrible job,

took a chance on getting deathly ill

and a lot of them you know, survived.

(Ambient music)

But in 1943

a scientific breakthrough meant the beginning of the end

for the waverley hills sanatorium.

The antibiotic streptomycin was developed,

it was the cure the world had been waiting for.

Without streptomycin or a similar antibiotics

tuberculosis would still be a plague even in the developed world

where it's rarely seen.

It's no longer needed in the 21st century

but it's such a monumental building

it has reinvent itself in order to find a purpose today.

Closed as a tb sanatorium in 1961,

waverly hills is now frequented

by people looking for something entirely different.

If an unmerciful god allowed the souls of the departed

to roam the world

then this is just the kind of place people imagine

unquiet spirits would be.

A nurse who got pregnant by a doctor who was married to someone else

mysteriously was found hanging out here in the hallway

across from the elevator car.

Just it right up there is where she was found,

was she just overcome?

Or a lot of people think that maybe something more sinister happened.

No-one will ever 100% for sure know exactly what happened to her.

(Dramatic music)

For most of the world

tb is seen as a disease of the past

but recent studies have suggested that might not be the case.

The original strain they can pretty much take care of,

the problem is there's a new strain coming out

that is very antibiotic resistant

and the old treatments just aren't working.

Tuberculosis is nature continuing to this day

to claw at human life and to force us to fight back.

Scientists across the globe are racing to find treatments

for this new strain of tb

and entirely new viruses and diseases that threaten a global pandemic.

It's almost like an arms race with these terrible diseases

and we hope that we're winning but it's a close battle.

Despite their devastating effects

these battles bring humanity together in new and inspiring ways.

(Cheering and applause)

(Dramatic music)

On the Italian island of sardinia,

in the blue waters of the mediterranean

an intriguing ruin clings to a cliff face.

You see this structure that just boggles the mind,

it looks like some ancient building

but it starts maybe 100 feet up this rocky cliff.

Has some of it fallen away?

It's a really strange juxtaposition

from cliffs to something that's almost like plastered on the side.

Now it might look on the face of it

that there's been an engineering catastrophe here

and the cliff face has fallen away

but no, this is purpose built

and what you see is what you're supposed to see.

Inside the full extent of the complex is revealed.

The tunnel itself is quite extensive,

it goes several 100m into the mountain,

you have to have a big incentive

to blast your way through such hard rock.

Ultimately you see there's two levels of tunnels

and you can see that there is a series of bins

in between the two tunnels

with some kind of gate at the bottom of each bin.

This is an amazing site with great ingenuity

and it really is what gets people into engineering.

You give someone a problem

and with enough imagination

they come up with an amazing solution.

(Dramatic music)

Antonio littarru is an expert on the history of this place.

Even during the Roman era, prisoners came here.

They were doomed to work here

and we have a particular term "damnati ad metalla,"

they were damned, condemned.

And yet this structure is far from ancient.

It's not as old as it looks actually

and it's quite beautifully engineered,

this was not an ancient monastery

or some kind of strange castle.

This was something industrial.

A closer look at the tunnel walls

reveals the type of rocks that are buried in the hillside.

You've got rocks that are very, very old

and rocks that are very, very young

and all through those different eras

you get times when you're having magma

which causes mineralisation

and causes things like silver and lead and zinc.

Along the coast visible from this cliff face

are the remains of a sprawling complex

that hints at an operation on a truly industrial scale.

You can see rail tracks, huge storage chambers,

all sorts of things going on, on an epic scale.

(Dramatic music)

You're almost dwarfed by these rusting bits of machinery

and it's clear that somehow this tunnel,

these two places were linked.

One of the biggest challenges of mining here

is getting the ore off the island.

For centuries there was no real infrastructure.

In the first part of the 20th century

the material was transported by the so-called galanziere.

They were basically like miners that transported this material

on their shoulders in little basket cases.

The lead and zinc ore was hauled to the coast by ox and cart.

As men and beasts of burden alike

toiled in the baking sardinian sun.

And from there things only got even tougher.

You have hard rock, hard basement rock

you often end up with rugged rocky coastlines,

cliffs, inaccessible areas,

so they don't necessarily lend themselves to big ports.

Small boats transported the ore to the nearest deep water port,

that was 15 miles across the treacherous open sea

on the island of San Pietro.

The area itself is quite precarious in terms of weather.

You've got the mistral winds,

these cold winds coming down from the north west off France

and you've got the (indistinct) Winds that come in from the west.

These boats can only hold about six tonnes of ore,

that's a remarkably small amount, I mean that's really,

that's just a few wheelbarrows full of ore

and they would load them as heavily as they could

so now you've got this little open boat

trying to get to a harbour some distance away

where it can be loaded in to a bigger boat.

It's full of rocks, these boats sank all the time

it was incredibly dangerous, slow, inefficient.

They're quite precarious little boats

so you can imagine you're loading a boat full of rocks

and then you're trying to get it off,

if you got bad weather those boats could easily topple over

and many did and many people fell to their deaths.

To solve this age old problem

the mine owners turned to venetian engineer

cesare vecelli.

And this guy was a real genius,

one of those out of the box thinkers.

Vecelli spent a year studying the problem

and studying the geography around the mine and the coastline.

They found this sort of wonderful site

where a sea stack was actually protecting

the waterway between the sea stack and the land

and it was deep water

so in principle you could get big ships in there.

But then your issue was creating a port.

Vecelli's solution was porto flavia.

Instead of taking the ore to the ports,

they would bring a port to the ore.

He said instead of building something new

why don't I use a structure that's already there.

Normally any mariner looks at this coastline,

looks at that cliff, this is their worst nightmare

and yet here they were planning to turn this forbidding cliff

in to a port facility.

Construction began in 1923

and the teams here worked day and night for two years.

Now all they had to do was blast out thousands of tonnes of rock.

They finally broke through the cliffs

and they could see the sea

but they didn't stop there.

And then here comes the really scary part,

they started hanging out over the water,

that way as they dug the tunnel

they could just shovel all the rock out in to the water

and again they repeated the process of drilling and blasting

until they'd carved out a parallel tunnel

below the other one.

The miners then dug nine vast chambers

connecting the two tunnels.

The silos are huge, 20m high

and between the nine of them

they could hold up to 10,000 tonnes of minerals.

This is the mechanism they used

to open the higher mouth of the hopper,

you see right here.

This opened and a lot of material came down from above.

Here once we had a moving belt.

With the final machinery installed, the system was complete.

(Dramatic music)

Electric trains from the mine arrived at the upper tunnel

where the ore was poured into the nine huge silos.

Meanwhile large cargo ships waited

in the calm waters below porto flavia.

In the lower tunnel

the ore poured on to the conveyor belt

before a 50 feet long retractable arm

which extended out over the sea

dropped it in to the ships waiting below.

At the end of that boom

was kind of a rubberised sleeve so as all those,

that gravel and rock was tumbling down

it wasn't just going to spray everywhere

it was all going to go directly into the hold where it belong.

In fact they could turn round one of these ships in two days,

loading up to 500 tonnes an hour directly in to the hold.

So a really amazing engineering feat

and they used the cliff and the geology

and the whole function of gravity really

to aid them in that process.

Porto flavia was a huge success.

It slashed production costs by up to 70%

but increased efficiency came at a price.

It produced a lot of wealth for the company,

and for this reason

a lot of the galanziere, the workers there,

lost their jobs.

Global forces eventually put an end to the ports good fortune.

Sadly the company didn't have that many years to enjoy

the efficiency of their brilliant engineering.

At the end of the 1920s you had the stock market crash

and then the great depression

then you had world war ii,

it reopened for a few years in the 1950s

but by the 1960s there were new efficiencies,

new technologies.

The last shipping occurred

in may 1963.

And since that day

it has remained in the memory of citizens,

and miners, and workers.

Porto flavia is now preserved for visitors.

It's both a testament the vision of one great engineer

and a tribute to the lives of generations of sardinian miners.

This port shows engineering at it's best,

you throw someone a challenge

of how to get a huge amount of material out

when nature is against you

and they came up with this incredible imaginative solution.

(Dramatic sound)

On the banks of the black sea in southern Ukraine

is a port city founded

by Catherine the great.

The stylish architecture above ground gives no clues to what lies beneath.

Every so often you hear a story of some young people who go down

and someone gets lost and doesn't make it back out again.

Some researchers say that we have approximately 800 accesses.

These access points range from the obscure,

to the downright bizarre.

When you look at this shed,

it might just be some kind of equipment shed.

And then you go inside

and realise it gives you access

to the most incredible underground labyrinth

anyone has ever seen.

It's absolutely quiet place,

the silence is 100%.

As soon as you switch off your torch,

then the, the darkness is absolute.

Few people walking the streets of Odessa

realise what lies beneath their feet.

As you go down,

it's clear that it's not just a normal set of tunnels

it's actually much more grand than that.

They just don't understand that they are literally walking

above the underground city.

It's the biggest such system, in the whole world.

A subterranean system perfect for a criminal underworld.

Yet it also served as the city's last line of defence

against an occupying force.

A resistance movement, that formed part of a horror story.

So, month by month passed, they began to get insane.

Increasingly disoriented underground.

These Russian secret police...

..Begin to hunt each other.

(Eerie music)

The city of Odessa owes it's very existence,

to one of the world's most iconic female leaders.

The Russian empress Catherine the great.

Wanted to build a new port city.

In order to open up the south of Russia to commerce.

A mighty port.

Where the three great rivers

of Eastern Europe came together.

The bug, the dnister

and the danube.

They desperately wanted access to a port on the black sea

and via that, the mediterranean

and the rest of the world.

In 1794,

Catherine approved funding for Odessa

which soon became a Russian trading super hub.

So, Odessa went from being a...

..Basically a village to a large city almost overnight.

They had a problem though,

in this area there aren't a lot of trees.

It's grasslands

and farms.

So, for building materials

they turned to the local stone.

And luckily they were sitting on a particular type of limestone

which is very, very good for making buildings out of.

So, they used the geology

of the rocks beneath their feet.

This gave birth to a subterranean world that pavel zagnyboroda,

now explores for a living.

Local authorities they try

to control it somehow but it's almost impossible really.

No mobile phone connection,

no radio communication.

No GPS signal reaches that deep

so, you can rely only on yourself,

on your own knowledge.

Yet even he may never understand

the full extent of this system.

No-one's really sure.

But one estimate is that there's about 1,500 miles of tunnels.

Now if you, if you put that in to context,

Paris has got about 150 - 200 miles of tunnels.

Rome maybe about 300 miles

so, it's three times both Rome and Paris combined.

The layout of these tunnels

is extraordinarily complex.

And it's not just on one level, they go down on multiple levels.

So you've got a kind of complexity

in terms of the different types of rooms and corridors.

But also it's multi-tiered,

it's actually on different levels, they've used different parts

of the geology in different ways.

It really is a labyrinth underneath the city.

You can imagine how someone could become...

..Dangerously lost down here.

But also how someone who really understands the network

and knows their way around, could use it to their advantage.

And in the city's darkest hour this world beneath the surface,

would offer a glimmer of hope.

During world war two the Romanians were allied with the Germans

and they attacked Odessa and took it over in 1941.

The Soviets pulled out,

but they actually left behind

some secret what you might call like special forces.

A group of Soviet secret police.

A group of the chequer from Moscow.

And another group from the Odessa office

are sent down in to the catacombs.

At the head of these units

were major's kuznetsov and colossian

and pavel has discovered signs of their time here.

Kuznetsov and colossian.

These group was exactly here, we found some bullets,

some batteries for radio station, some guns as well.

They were well trained and prepared to act as a partisan.

So, they had water, food, guns...

..Explosives,

mines whatever they needed for a long time to stay here.

But they weren't prepared for the psychological challenge,

the isolation, the darkness.

You know we hear about people

on polar expeditions who really struggled.

Imagine if you're down in a tunnel for six months

without seeing the sun,

maybe only able to light a candle once in a while.

Some of the men turned violent, perhaps suicidal.

They also had to contend with the invaders

using poison gas in the catacombs

and sealing exits

in an effort to trap and smoke out the rebels.

Here, danger lurked around every corner.

Of course partisans are always vulnerable you know,

it just takes one person spilling the secret.

Along with kuznetsov

is evgenia (indistinct).

And she is a traitor.

(Indistinct) A member of the surface team

betrayed her unit.

She turned informer

telling the Romanian security forces everything she knew.

We don't know why she did this, she betrayed all of them.

First of all they arrested all 13 people in the city of course

and then they blocked all the exits for this underground team.

But evgenia (indistinct) Betrayals

were eventually discovered by her compatriots.

So, she is put on trial in a brief informal people's trial

and put up against the walls of the catacombs

and she's shot dead.

(Gunshot)

But now,

the two groups of communist partisans

mistrust each other fatally.

They began to get insane.

So, they really got absolutely mad

after approximately ten month, they begin killing each other.

(Dramatic fast music)

The two of them, hunt each other...

..In a silent vendetta.

And in the end none of the Soviet partisans,

emerges from the catacombs alive.

Having dispatched colossian and his Moscow team.

Kuznetsov had finally been killed by one of his own men.

But declassified documents

later revealed that one man did survive to tell the tale.

So, he came to a security services of Soviet army

and they came here.

And so he showed them everything.

And they just showed him death in his back right here.

On the third day after the liberation of the city

he was killed by his own people,

after three years of this terrible hell underground.

And so, the last living eye witness

to this horrific tragedy had been removed.

It appears that the Soviets

were not about to allow the reputations

of their heroic resistance fighters,

to be tarnished by the realities of the story.

Because for propaganda

they needed absolutely a different story.

It may seem that they all,

all these people, all these partisans

they died for nothing.

Like in, completely in vain.

But it's not true

because Romanians they didn't know

how many exactly there were partisans hiding underground.

Tens of thousands of troops

were stationed here throughout the war

to save the city from their unseen enemy below.

I think that it was this huge contribution

of these partisans in to the victory.

(Eerie sound)

Pavel now runs part of the catacombs as a museum.

Bringing centuries of history to life.

From the city's birth through piracy and smuggling

right up to the nuclear bunkers of the cold war.

On the edge of a bay in the south west of Japan,

is a complex that's been towering over the land for decades.

(Dramatic sound)

This is set in beautiful landscape,

there's water and trees everywhere and then right in front of you

these three huge towers are just there.

They're massive.

We're looking at a really tall...

..Four-500 foot high towers.

Very slender tapering upward, like almost like concrete needles.

They look almost like smoke stacks.

If you can take a peek inside the tower

you see a long, precarious looking metal ladder

going up to the top.

Whoever had the job of climbing that ladder

certainly didn't suffer from vertigo.

The fact that there's three of them

it makes you question why wasn't one good enough?

Why did there need to be three?

Only when it's viewed from above,

is that question answered.

They form a perfect equilateral triangle

and then at the centre of this triangle

is some sort of a building.

It's so overgrown,

it's been forgotten,

that building has been completely wrapped up

by the plants and trees that surround it.

Inside the building there's not much there,

clearly this was an important installation of some sort

but when it shut down whatever was there got taken away.

The complex is linked

to the gravest military disasters in u.S history.

(Suspenseful music)

But the bare rooms in the hollowed out towers

paint an incomplete picture.

Whatever these towers were built for

you don't see a lot of infrastructure,

there's no lights or cables or other things,

is there some other piece of the puzzle that's missing here?

(Drumming music)

Dating back to 1918.

The towers have stood guard over the site for more than a century

thanks largely to their once cutting edge design.

Hideaki matsuo is a historian

with a deep knowledge of their construction.

Translation: "If you head to the back

"you can see the lines in the wall,

"each layer is four-and-a-half feet tall.

"After the first layer you have to wait for another two days

"before you can add another one on top.

"And after completing 100 layers

"this 446 foot tower was finished."

The decision to build the tower with reinforced concrete

despite the high costs and the slow rate of progress

indicates how important it was to get the construction exactly right.

It took four years to build this

at a cost in todays dollars,

of nearly $15 million

which speaks to the sophistication

of the technology employed.

(Dramatic music)

Looking like an industrial chimney from the outside,

the central winch system shows that this was really

all about reaching new heights.

Translation: "When you go to the back there is a ladder.

"It's the original one

"and there are 550 steps to the top.

"To reach the top takes 55 minutes

"and you have to keep climbing without a break.

"There is nowhere to rest in between,

"it is quite a hard climb and it's slow.

(Eerie music)

Today an aircraft warning light

sits on top of each tower.

But years ago, there was some very different equipment here.

What's missing from the structures today are the aerials

which were in the form of triangular frames

and they would have sat on the top of the towers.

Between the towers were connecting wires

and that linked all of them so they became one.

Together they were used to transmit radio signals over great distances.

Radio waves come in a range of wave lengths

from very short ones to very long ones.

And it's the long waves that most easily travel long distances

but to create a long radio wave

you need a very big antenna.

The towers were part of the hario wireless telegraph station.

They were designed to remedy a long standing and costly problem.

(Dramatic music)

One of the forgotten wars in world history by many,

is a brief war between Japan and Russia in 1904.

But it was a time when Japan actually tried out a lot

of their technologies and in that war

they really learnt the importance of good communication.

Prior to radio communication,

the standard way of sending a message between ships was by flag.

Navies around the world developed very sophisticated systems

using flags and other signals where they could communicate

from ship to ship and coordinate their activities.

But communicating from ship to shore

was always a problem, once you were over the horizon,

you were on your own.

In the modern world of the 1920s and '30s

flags were outmoded and outdated.

Japan would soon start trying to expand,

they had imperial ambitions

and so communication was Paramount to this.

They wanted to measure themselves against Great Britain,

against the United States,

against the French empire, against the Russians.

And so for this they're going to need

a really modern communications array,

so, that Tokyo central

can communicate with the Japanese Navy wherever it is.

There were actually three complexes like this,

one in Taiwan,

one near Tokyo

and this one close to Nagasaki.

The three could communicate with each other

so, you could rely a message from one to the next and beyond

but they could also broadcast messages far out over the ocean.

You had better communications, better information,

you have a huge edge in any military conflict.

There was one building here

that was vital for success.

It was crucial to the Japanese military victories of the 1930s

and as the second world war crept closer

it was about to be put to use again.

It may also have had a part

in one of the gravest events in u.S history.

Translation: "This is the rooftop of the telecommunications room,

"it is also the centre of the three radio towers,

"those radio towers are positioned in an equilateral triangle

"almost 1,000 feet apart from each other.

"And this is located right in the middle of those towers,

"which was important.

"Cables coming from those three radio towers

"were connected to the telecommunications room

"but the telecommunications room itself

"was hidden underground."

With war on the horizon,

meticulous preparations were carried out.

The facility was made highly secure and self sufficient.

The building housed the power to run the whole operation

in the form of generators and batteries

but it was also where communication

was sent and received.

Messages would be picked up by the towers,

relayed to this building,

decoded and then retransmitted

to their original destination.

This dark space certainly had the potential to cause untold damage.

Translation: "This room was where they transmitted the secret codes

"that were created in sasebo.

"From the size of the room

"and because we know there used to be five or six desks in here

"we presume that there was a small number

"of transmission workers in here.

"However as they were dealing with highly confidential documents

"I don't imagine many people were allowed in."

In 1941,

a top secret coded order

that shaped the course of history,

is likely to have filtered through these rooms.

There's good reason to believe that one of the most

pivotal radio transmissions in history

was made via this transmitter.

The words, 'climb mountain itaka 1208'.

Those words were code

to send the instruction to proceed

with the attack on Pearl harbour.

(Dramatic music)

Once the order had been given by Tokyo

it's believed that hario

actually transmitted the fateful message

from mainland Japan,

to the waiting naval fleet.

The attack on Pearl harbour was devastating

and it immediately drew the United States into the war.

But questions about hario

and it's role in all this

remain unanswered to this day.

Translation: "There's almost no documentation remaining

"about the hario radio site.

"Architectural drawings,

"records of transmission history and so on,

"they don't exist at all.

"The reason being that straight after the war ended

"any related documents were burnt."

While the Japanese may have destroyed

any incriminating and damning paperwork

they couldn't make the very real concrete evidence here disappear.

We can't say for sure that the order

to attack Pearl harbour came from hario because after the war

the Japanese destroyed all the records that were stored there.

But given the configuration of the various transmission sites in Japan

it probably came from here.

Today the prominent towers,

help to caution another generation

not to repeat the mistakes of the past.

And it's hoped that they'll continue

to sound their warning for many years to come.

These towers were designed to last for about 90 years

but the way they were engineered and constructed

means that they'll last for a lot longer than that.

Captioned by ai-media ai-media. TV