Original subtitles

[narrator] A Moroccan stronghold governed by a ruler with friends in high places.

[intense music playing]

[Bell] Charlie Chaplin, Winston Churchill,

General George Patton.

They all came to pay homage.

[intense music continues]

[narrator] In the Czech Republic,

a place of hope in an age of tyranny.

[Dr. Nusbacher] He was watching the Holocaust happen.

He had to move people to where they might have

a fighting chance of survival.

[narrator] And an Amazonian paradise

that fell victim to the lure of reality TV.

Celebrities and dignitaries

all made the same trip to this stretch of jungle

that proved to be both a blessing and a curse.

[intense music playing]

[narrator] Decaying relics...

Ruins of lost worlds...

Sites haunted by the past...

Their secrets waiting...

to be revealed.

High in Morocco's Atlas Mountains,

an isolated settlement appears like a mirage,

straight out of The Arabian Nights.

[dramatic music playing]

Large areas are in ruins, but it is a pretty imposing structure.

It has high walls and narrow windows.

It doesn't shrink into the landscape, it dominates it.

This place was clearly fortified.

[narrator] Yet, behind the mud brick ramparts,

a labyrinth of unexpected grandeur awaits.

Every passageway leads to something completely different.

Either a crumbling ruin or a beautiful room covered in mosaics.

[narrator] Built by a dynastic family of great influence,

it evolved into the lavish outpost of an enigmatic leader.

Up here, a mountain warlord rose to become one of the most powerful men in Morocco,

and one of the wealthiest in the world.

[narrator] Yet hubris would lead to his downfall.

To some, he was a pragmatist who saw the imperial tide crashing in and adapted.

To others, he was a traitor to his country.

[intense music playing]

[narrator] Brice Bexter is directly descended

from the powerful clan that once occupied this site.

[Bexter] I first came here in March 2020

in order to discover where I was from.

It does give me goosebumps.

My ancestors started our family's name and our family's legacy here.

[narrator] Yet, under the rule of Brice's controversial great-grandfather,

Thami El Glaoui,

the family's legacy was tainted.

[Bexter] It is...

undeniable our name comes back a lot in the press,

whether it's positively, whether it's negatively.

I don't think my great-grandfather was a perfect person.

Uh, definitely not.

But I also always tell people to not judge their history 100 years later.

[narrator] This is Kasbah Telouet,

the extravagant seat of power of the El Glaoui family

that first rose to prominence in this region 200 years before Thami took control.

A kasbah is essentially a fortified residence for a ruler.

[Luke] They often house key buildings

like garrisons for troops, mosques, and residences.

They also guarded trade routes which is why this one is located here.

[Bexter] That's how the family slowly and surely built

its strength by controlling taxes

and caravans as they were coming through ins and outs of Morocco in the south.

[narrator] By 1860, the El Glaouis had amassed enough money

to build this commanding symbol of dominance.

As their wealth increased from salt, saffron, and the olive trade,

so too did the size of their kasbah.

Over the centuries, every one of my ancestors added their own touch

and you can see the evolution of all the different time periods.

[narrator] The biggest change was still to come.

In 1893, a rare event provided the family an opportunity

to elevate their status even further.

At the time, Brice's great-grandfather, Thami, was 14 years old

and served as second-in-command to his older brother, Madani.

The sultan of Morocco was in the Atlas Mountains

when he and his men were caught in an unexpected snowstorm.

My great-grandfather and his brother brought them back here

until the harsh winter passed, so they had to feed an army of 3,000 people

as well as the king himself.

In return for their hospitality, the family was given political power

over Morocco, south of the Atlas Mountains.

He gave the Glaoui a 77-millimeter Krupp cannon.

And this was the only weapon of its kind in Morocco outside of the Imperial Army.

The Glaoui used this weapon to subdue rival warlords.

The whole region was mostly in their hands during that time.

[narrator] The El Glaouis' stronghold grew to reflect

their unrivaled wealth and authority.

[Bexter] This is the main entrance to the kasbah.

And so, when my ancestors used to welcome the people,

they were always coming through this courtyard first.

[narrator] The farther in you went, the more exclusive the spaces became.

So we're in the riad. In Morocco, riads are open courtyards.

All of our houses always have, like, a common area

with most of the time, a fountain in the middle.

Well, here, you don't have much left of it.

But you can get an idea of what it used to look like.

[narrator] Below ground, Brice finds the quarters of the servants

who supported the family above.

You can hear the bats.

So, we're under the main room here. And it's not always safe.

But it gives you access to the upper parts,

and ways for all the employees to get around the palace.

[narrator] By 1909, although Thami had not ascended to be head of the El Glaoui,

he had still made full use of his family's influence

to secure the coveted position of governor, or pasha, of Marrakech.

Three years later, the world outside the kasbah walls was changing

and Thami's time would come.

In the European scramble to divide up Africa,

Morocco lost its independence to France in 1912.

[Bexter] The French quickly understood that in order to do anything

in southern Morocco, you would have to ally yourself with the pasha.

For the younger El Glaoui brother, this was a moment of reckoning.

He could either fight for independence,

or cast his lots with the new European powers.

[narrator] In 1912, after the French conquest of Morocco,

Thami El Glaoui, the Pasha of Marrakech,

was left facing a stark choice.

To join the foreign invaders or stand by his country against them.

For a man of his ambition, there was only one option.

El Glaoui sided with the French.

And in return, gained rule over a large swathe of Southern Morocco.

[Bexter] My great-grandfather was quickly associated as a collaborator with the French.

So, obviously, he was considered a traitor by most of the people.

[narrator] Then, in 1918, after the death of Thami's older brother, Madani,

the French further repaid his support by appointing him as head of the family,

instead of his siblings' sons who where the rightful heirs.

Over the next two decades, Thami leveraged his position to consolidate his wealth

and become one of the world's richest men.

[Bell] This was the pinnacle of his power and influence.

And this was a man who enjoyed flaunting it.

This was built by my great-grandfather back in the 1930s.

Of course, he liked to show off.

You know, like anyone who's successful in life at some point, I guess like...

You wanna show, you know, the extent of that success, so yeah, it was a statement.

He amassed so many riches that everyone either wanted to see or be seen with him.

[Luke] Charlie Chaplin, Winston Churchill, and General George Patton

all came to the kasbah to be hosted by the Pasha.

[narrator] But as the 20th century wore on,

Moroccan nationalist tension grew under continued French rule.

El Glaoui, still aligned with the colonialists,

was about to make a fateful decision.

And no amount of powerful friends could save him.

In 1953, he conspired with the French to overthrow Sultan Mohammed V.

[Bexter] It was intense. It was a lot of pressure.

And that came from the French being around

and wanting to keep their, their hands on Morocco as long as possible.

[narrator] Thami El Glaoui had misread the mood of the nation.

[Luke] An independence movement to Morocco was simmering under the surface.

The next two years was an eruption of violence

and a unified demand for the return of their sultan.

In 1955, the French were forced to concede and bring him back to Morocco.

And this spelled disaster for the Pasha.

In an extraordinary scene, the Pasha was publicly shamed

when he was brought to Paris and forced to beg and grovel at the Sultan's feet.

It was the end of a stunning fall from power.

The Pasha died just months later.

[narrator] In March 1956, two months after Thami's death,

Morocco gained independence.

The impact on Kasbah Telouet proved fatal.

That's when most of their palaces, most of their goods,

and most of their fortune was seized.

We did get the place back in the late '80s.

But I mean, the state of the kasbah was already totally degraded.

So, we were left with almost everything you see today.

[intense music playing]

[narrator] Now reunited with his family's property,

Brice must come up with inventive ways to keep the kasbah standing.

I was lucky, I guess, to bring a movie set here

that had this Arabian Nights feeling to it and it was beautiful to be able to see

what was it like to live again like this and to be able to imagine

what it would have looked like back in the days.

[narrator] In the Czech Republic, 100 miles east of Prague,

a rundown facility tells an extraordinary tale

of deception and survival.

[Onyeka] This looks like an ordinary Czech town

but in the center, there appears to be abandoned warehouses

configured around a central courtyard.

What was its purpose?

[Selwood] Inside, you see raised concrete plinths

and sturdy pillars holding up the floor,

all of which suggest that this place was once filled

with heavy machinery of some sort.

[Dr. Nusbacher] You see there are sacks of fiber and there are bobbins.

So clearly, there's some textile industry going in here.

This structure seems to be part of an operation that's been forgotten by history.

[narrator] Yet within these walls, an improbable savior

risked everything to defy a ruthless killing machine.

[Onyeka] He was an entrepreneur, a spy, and a playboy.

And he conned one of Europe's most dangerous regimes.

There's no doubt, it's one of the most important stories of the 20th century.

[Selwood] The events that took place here inspired an Oscar-winning movie

known as Schindler's List.

[intense music playing]

So I first came back in 1973 when I was very young and with my father.

This was my grandfather's factory.

This is where he worked with his two brothers.

[narrator] Dr. Daniel Low-Beer is the custodian of this site today.

In the early 1900s, this was the beating heart

of his ancestors' thriving textile business.

[Daniel] Our family had been here for many hundreds of years.

And they felt very much part of this land.

They were accepted in Czechoslovakia.

This is where the Jews could express themselves fully culturally.

[narrator] But in 1938, the rise of a terrible evil

left Daniel's grandfather, Walter, staring into the abyss.

So, from one day to the next, Czechoslovakia is one country and then it's split into two.

And the border goes along the stream that goes through our factory.

And my grandfather wakes up and on the other side of the river

is a battalion of Nazi soldiers who had come in

partly to invade, partly to loot, partly to find what they could.

He said, "You can't come over this river. This is the border.

Go and check your orders and your borders." And he held them up.

A Jew on that border, holding up the Nazis for three days.

[narrator] Walter was just one man standing against an entire army.

Shortly thereafter, the Low-Beers were forced to flee,

leaving their life's work behind.

In the early years of the Second World War,

a variety of companies worked at the factory,

producing textiles and armaments for the German war effort.

[narrator] Then, in 1944, the site underwent a horrifying transformation.

[Daniel] This was a concentration camp.

So you first of all have to imagine the barbed wire which closed it off.

The watchtowers which would be looking over this place.

There was 80 to 100 armed SS guards here,

some of them extremely dangerous.

[narrator] Around 1200 Jewish captives were transported

from Poland to work in this labor camp.

But the Nazi industrialist who brought them here had an extraordinary secret.

[Dr. Nusbacher] What this place produced was hope.

And that's a precious commodity in dark times.

[narrator] In the Czech Republic, is the site of an old textile factory.

During World War II, it was seized by the Nazis

and turned into a labor camp to make weapons.

But for the man in charge of the facility,

it had a hidden purpose.

[Onyeka] He certainly was no saint,

he didn't regard himself as an humanitarian,

but even ordinary people can behave in extraordinary ways.

[narrator] His was Oskar Schindler.

And this was to be a safe haven to protect a people under siege.

At the start of the war, his motivation could not have been more different.

Schindler is getting rich taking over factories that belonged to Jews.

Schindler is coining money, he was stuffing his pockets 'cause he's a Nazi,

he's friends with Nazis, there's Nazi money to be made.

And Schindler is living well.

But somewhere or sometime during the Second World War,

he began to change his perspective.

People are being taken from Poland's ghettos

to Poland's death camps

and they're being murdered on a wholesale basis.

Schindler was watching the Holocaust happen.

[Selwood] It seems that it was during this period

that Schindler's motivations changed.

If he had done nothing, all of his Jewish workers

would have been deported to extermination camps, most likely Auschwitz.

[narrator] It was then that Schindler came up with a plan

to outsmart the Nazis.

His path to redemption had begun.

[Onyeka] Oskar Schindler, with the help of his employees,

began to draw up lists.

Lists of people who would effectively be saved

by working at his labor camp.

Schindler told the SS that those on the lists were highly-skilled workers

and essential to setting up and running the factory.

[Dr. Nusbacher] Schindler needs to insulate the people he's trying to save

from the deadly, casual brutality of the SS guard force.

By housing the workers inside the factory,

and the guards in a separate building,

he reduced the likelihood of these attacks.

[Daniel] So there's three floors, the first two would be used for production.

And they would have lived above this floor.

This was a relative place of safety.

[narrator] From the very start, Schindler had no intention

of using his factory to make weapons.

Yet, he had to convince Nazi officials of the exact opposite.

Schindler has got to pretend that he is building German armaments

in his factory even though

he's producing approximately no German armaments.

It was tense from the morning to the evening. There was danger everywhere.

And when the inspections came, yeah, there would be a huge flurry.

He would have to find munitions, he would have to forge documents.

[Dr. Nusbacher] Every hour, every day, every breath

that those people took was an act of defiance

against the Nazis.

[narrator] Schindler and his workers maintained the deception for over six months

until Germany's total surrender came on May 8, 1945.

But only the Jewish prisoners knew Schindler's secret.

In the eyes of the advancing Allied forces,

he was a wanted Nazi war criminal.

It's at five past midnight that the roles change.

He was in charge of his camp, and then suddenly, becomes the hunted.

[narrator] Some of the workers put together a letter,

explaining that Schindler had done everything he could

to save the largest number of Jewish lives possible.

It also asked anyone he showed the letter to

to help him in any way they could.

[dramatic music playing]

[Dr. Nusbacher] But paper burns,

and ink dissolves.

So they made him a ring.

[Daniel] And there's no gold

anywhere, apart from on their teeth.

And so they melt this ring out of their teeth.

But on it, there's a phrase which is taken from the Talmud,

which says, "If you save a life, you save the world entire."

[narrator] While the workers waited

for the camp's official liberation,

Schindler fled west to American lines

with the letter, the ring and a remarkable story.

He had helped save 1,200 people from the Holocaust.

[Dr. Nusbacher] And it is estimated that

the descendants of those 1,200 people,

7,000 to 9,000 people

are alive today,

because Oskar Schindler risked everything

to save the lives of people to whom he owed nothing.

[Daniel] It's not clear why

he did what he did.

But in some ways, that's what

keeps the story alive,

and allows the next generation of children to make

their own mind up.

And then, most importantly, what would you do

in the same situation?

If Schindler could do it, why couldn't more people do it?

[serene instrumental music playing]

[narrator] In 2019,

Daniel was able to buy back

his family's old factory.

Today, he is working to turn this site into a museum

dedicated to those who survived here.

[Daniel] In the Jewish sense, when the world is shattered,

you wanna put it back together again.

And I think it's a little bit the impetus we have here

in this ruined factory,

is to put something back together which can tell a story,

and show survival.

[narrator] In Brazil,

deep in the Amazon rainforest

are the neglected remains of a pioneering venture.

[intense music playing]

[Gutierrez-Romine] As you navigate through the waterways,

you come across this ruin that's just

rotting on the side of the jungle.

There is this mess of stilts

and beams, and they

reach up hundreds of feet into the air.

You can see the remains of a boardwalk

and some platforms teetering high above the water.

[narrator] As more skeletons emerge from the forest,

the extent of this site becomes apparent.

[Gutierrez-Romine] This area is

remote and exposed.

It's not exactly a place where you would

imagine there to be a settlement.

[Michele] This is a footprint of a vast complex.

To build somewhere like this would have required

specialist local knowledge.

[Morgan] It makes you wonder, why

was this created?

Was this some sort of an industrial facility?

[Gutierrez-Romine] This place was built with

one thing in mind.

An existential threat to humanity.

[narrator] In the heart of the Brazilian rainforest,

are the fallen remains of a bold enterprise,

conceived with a noble intention.

[Roberto speaking Portuguese]

[translator in English] Everything I have, including my family,

comes from here. Best friends were made here.

So, looking at it now, in ruins,

it's hard to talk about.

[narrator] Roberto Abdias has worked

in the Amazon all his life.

For 17 years, this was home.

[Roberto speaking Portuguese]

[translator in English] As a jungle survival guide, every day there's a connection

with nature.

It is something inexplicable.

[narrator] Today, these derelict ruins

are only accessible by boat.

When first built, a helicopter was

the favorite method of transportation for those

who could afford it.

[Morgan] To see it now,

you wouldn't think that some of the richest people

on Earth came to visit this. But they did.

[narrator] Its story began

with a chance encounter more than four decades ago.

[Gutierrez-Romine] In 1982,

one of the most renowned

explorers, Jacques Cousteau, came and visited this part of the Amazon.

He explored the world, and he brought attention to matters

like the disappearing rainforest.

[narrator] It was while staying at a hotel in the city of Manaus,

Cousteau grew close to its owner,

Francisco Ritta Bernardino.

[Michele] Cousteau made a prediction to his new friend.

He predicted that, within 15 years,

the whole world would be talking about the Amazon.

Not just climate scientists and biologists, but also regular, concerned citizens.

[Morgan] Bernardino

was inspired by Cousteau.

In an effort to prevent

further deforestation, he wanted to make a difference.

[narrator] He was also a keen businessman, with an eye

for opportunity.

When Cousteau encouraged him

to consider the fast-growing industry of ecotourism,

it seemed like the perfect fit.

This is all that remains of Bernardino's Ariau Towers Hotel.

[Morgan] By establishing a resort like this,

people could come and experience

the Amazon without damaging the Amazon.

They could take away from it memories without

leaving anything behind.

[Michele] This would be

a unique building that would immerse people right into the heart

of this incredible ecosystem.

[narrator] Bernardino began his ambitious project in 1984.

From the beginning, there were challenges to overcome.

For half of the year,

this area is under water.

-[Roberto speaking Portuguese] - [translator in English] He first went

and spoke to the local people.

"Look, you know how

to work with wood like nobody else.

I want to build a hotel on stilts.

And since the water rises and falls every year,

I need a specific wood that can be used on the water

and doesn't deteriorate."

And the local people knew how to do that, because they lived there.

[narrator] After two years of building,

Ariau Towers was ready to welcome

its first guests.

[Gutierrez-Romine] What Bernardino

achieved really was this massive

feat of construction and engineering.

He built on stilts

300 rooms, a helipad,

dining rooms and so much more.

[Morgan] There were walkways that linked one building

to the next.

There were catwalks that were

up in the trees, so that

you could experience the part of the Amazon

where most of the life lived.

They'd be able to see pink dolphins. They'd be able to see

any number of

brilliantly colored birds.

[translator] If those clients wanted more activities,

I would take them to the jungle and spend the night.

It was a spectacular thing that.

Staying overnight in the jungle was something from another world.

[narrator] Ariau Towers

tapped into a growing trend.

And its exclusivity attracted the rich

and famous.

[Morgan] This was built

in an era when problems with the Amazon rainforest

were just becoming

general knowledge, and the way that

that elimination of rainforest was also displacing

tribal people that lived in the Amazon rainforest.

At its height, it wasn't uncommon

to see celebrities or politicians here.

-[Roberto speaking Portuguese] - [translator in English] We had Bill Gates,

Kevin Costner,

Jennifer Lopez, Arnold Schwarzenegger

They came from Manaus

to this helipad.

[helicopter hovering]

[narrator] Business was booming,

and Bernardino's investment appeared to be paying off.

[Gutierrez-Romine] In the late '90s,

it is estimated that

revenue was somewhere around $12 million

from the 36,000 guests

it was receiving per year.

[narrator] Then, in 2002, a reality TV juggernaut

came calling, and it seemed like a lucrative opportunity,

too good to miss.

[Gutierrez-Romine] The hit reality series Survivor

was looking for a location for its sixth season.

And Ariau Towers fit the bill.

[Michele] The production went ahead

and they booked out the entire place for months.

[Roberto speaking Portuguese]

[translator in English] I even trained the reality participants.

And, by the way, they paid me very well.

But I guarantee you, I would rather have not earned that money,

and the reality show didn't happen here.

Because it was the reason that bankrupted the hotel.

[narrator] Ariau Towers

was headed toward disaster.

[Michele] It turns out that

interrupting your regular stream of guests for an entire three months

can really be disastrous in the tourism industry.

[narrator] In 2002, the reality series Survivor

chose the Ariau Towers Hotel

as the base for their latest season.

The production's high-profile presence was supposed

to attract new business.

Former hotel employee,

Roberto Abdias, believes it had the opposite effect.

[Roberto speaking Portuguese]

[translator speaking English] Big operators had to

cancel their groups because the hotel was rented

for a television show.

Imagine a group of 100,

200 people in a hotel

that could accommodate 700.

The number of visitors began to decline,

and soon there were

staff layoffs that followed.

[narrator] The hotel limped on for another decade.

But the business never recovered.

Operations ceased in 2016.

And the Amazon quickly reclaimed its ground.

[Gutierrez-Romine] All of the locals who helped to build

and operate Ariau Towers

really saw this as their own.

So, when the facility became defunct,

they took the timbers,

they took the beams and the roofs, leaving

very little standing there today.

-[Roberto speaking Portuguese] - [translator in English] I can confess to you

I also have a hotel door in my house, that I will keep

for the rest of my life as a souvenir

of a place that made me so happy,

that made me achieve everything I have.

[narrator] The Ariau Towers Hotel

may have ended in failure.

But Roberto believes it should be remembered

for the good it tried to achieve.

[speaking Portuguese]

[translator in English] The objective of the hotel

was to help preserve the rainforest

and generate income for the local people.

Thanks to the Ariau Hotel,

it educated a whole group that today are still working

in ecotourism.

It was the best jungle hotel

in the world.

[instrumental music playing]

[intense music playing]

[narrator] In Germany, just outside of Berlin,

a peculiar collection of buildings litters the countryside.

[Gutierrez-Romine] About 20 miles east of the capital,

this sprawling city gives way to these

portions of green and dark patches of woodlands.

[Meigs] Looking through the trees here, we start to see

some strange stone structures.

Some of them look like they might be

churches or maybe medieval forts.

One place we see something that

looks like it could be a temple In Cambodia.

[narrator] Exploring deeper, a confusing picture

begins to emerge.

[Gutierrez-Romine] There are long, dark corridors.

And there are deep holes

that lead to nowhere.

On the lower levels

are the remains of railroad track and old carts

It's hard to figure out what we're looking at,

or what was here.

[Michele] The rusting metal remains suggest that

this was some sort of industrial complex.

But for what trade?

[narrator] From the fires of this vast complex,

one of Europe's greatest cities was forged.

[Gutierrez-Romine] Just from looking at what is left here,

you would have no idea

of the role that this place played

in the building of modern Germany.

[dramatic music playing]

[narrator] Kathrin Jurkat is a historian

who works in the shadow of this towering behemoth.

The ground on which it's built

is the very reason it exists.

So 240 million years ago

at this site, there was an ocean.

There were shells and other animals living inside of it.

These shells, when they died, were transforming into limestone.

Limestone is a really great material to work with

as a building material.

It's easier to cut into different shapes than, say, granite.

And it's easier to quarry.

Berlin really is a city of limestone. You can find it

everywhere, from the floors

of the Berliner Dom Cathedral

to the roads of the working class neighborhoods.

[narrator] This is Ruedersdorf.

For over 750 years,

it was at the heart

of an industry that built the German capital.

But this site produced more than

Berlin's building blocks.

It also created

the vital ingredient that held them together.

This is the chamber kiln. It was built

in 1666.

And this is the oldest structure we have here

in Ruedersdorf. It was used

for burning lime.

[Meigs] The cooking of the limestone changes its chemical structure.

If you'd let it cool down, you could crumble

the rocks into a fine powder,

what we call quicklime.

Then, if you add water,

and throw in some sand and other things,

you would have cement.

[narrator] Quicklime's impact

on the city is impossible to overstate.

[Gutierrez-Romine] Berlin's population in 1701

had swelled to

over 100,000, and it was growing

in all directions.

As European society advanced, and bigger

and bigger stone buildings were being built,

the demand from these furnaces,

or kilns, was enormous.

[narrator] In order to keep up,

it was the poorly paid labor force

that suffered most.

Can you imagine

just how difficult and dangerous this work was?

They were moving chunks

of rock that were heated to 1,000 degrees.

[crackling]

[Gutierrez-Romine] If the burnt lime

came into contact with their skin

or their sweat,

which was inevitable in conditions like this,

it was like acid.

They could get very severe burns.

[narrator] Despite the risks,

there was constant pressure to keep the kilns burning

no matter what.

The entire procedure, however,

was incredibly inefficient.

[Meigs] The problem with this method is you have to load the kiln,

build this intense fire for four or five days,

you had to pull the limestone out

and repeat the process.

As demand for cement

increased, this method wasn't fast enough.

[narrator] But that wasn't the only issue.

The fuel that fed the fires

was also in short supply.

[Michele] The chamber kiln

needed wood to run.

But the Brandenburg forest was running out of trees

at an alarming rate.

[narrator] If Berlin's growth was to continue,

Ruedersdorf needed to find a solution.

Fast.

[narrator] Berlin was undergoing

a rapid expansion at the turn of the 19th century.

But the resource that fueled its rise

was under threat.

The city had depleted its supply of timber

to fire the quicklime-producing kilns at Ruedersdorf.

An innovation by British-American inventor

Lord Benjamin Rumford in 1802 would prove vital.

The Rumford kiln operates like

a kind of vertical conveyor belt.

Workers bring chunks of lime with carts

to the top of the structure

and they drop it into the central shaft.

[crackling]

There's fires that are kept burning at all times

around the shaft.

As the limestone cooks down,

they keep adding more limestone at the top.

But at the bottom, workers can open the shaft

and shovel out the cooked limestone.

Whereas before it had taken about a week

between loading and unloading the kiln,

this one burned continuously.

And instead of burning wood, which was running out,

it used peat for fuel.

[narrator] Peat burns hotter,

and there was an untapped supply in the wetlands

around Berlin.

This, combined with the Rumford kiln's ability to operate

24 hours a day,

365 days a year,

saw production triple.

The technological leap was good for business,

but did little to improve

the lives of the labor force.

So this great invention of the Rumford kiln

was not so good

for the workers.

Before that, they didn't work that long, but now they had to work

16 hours a day.

Also, it was very harmful for them to inhale the dust.

A lot of the workers here had a problem with their lungs.

[Michele] This really was not a healthy environment.

And, quite tragically, many workers

never saw the age of 40 as a result.

[narrator] Despite the human cost,

the kilns worked around the clock.

[Gutierrez-Romine] Even though

28,000 tons of quicklime

were being produced every year,

there was always a need for more.

[narrator] Berlin was quickly becoming one of the largest

cities in Europe.

In 1871, with the unification,

Germany became really a great power

for the first time.

And that led to a much faster pace

of economic and industrial development.

Berlin had become the capital city of the entire

German Empire.

And its population had reached 800,000.

[Meigs] They needed more raw materials.

They needed more cement.

[narrator] At this time, Ruedersdorf had

five Rumford kilns in constant operation.

It wasn't enough.

The answer was to build something even bigger.

[Jurkat] So this is the shaft kiln battery.

It was finished in 1877.

So, the innovation here is that

they put 18 kilns

right next to each other, so that

it functioned like a factory.

[Michele] This structure

was built in a kind of a ditch,

which at the top allowed railcars

to reach the roof, and from the bottom

carts could be loaded straight onto the railway.

[Meigs] This complex, located where it is,

is part of why Berlin was able

to grow as rapidly as it did.

This place helped build a lot of

what remains as kind of iconic Berlin today,

including the Brandenburg Gate.

[narrator] For almost a century

these kilns burned,

producing hundreds

of thousands of tons of quicklime,

fueling Germany's

path to become the nation we know today.

But by the late 1960s,

the once cutting-edge technology

was becoming obsolete.

And by 1967,

it had been abandoned.

Today, Ruedersdorf is open to the public.

It provides a unique insight

into a factory that built a city.

[Meigs] It's interesting that it was never

torn down or reused for other purposes.

And that's

really great because you can see

what's essentially a museum

and a tribute to all the hard work

and innovation

that went into developing these modern

building materials.