Original subtitles

[Male Narrator] How do engineers building the steepest railway

in the world overcome impossible odds

and tunnel through a freezing cold rock face?

[Bruno] It was blocked and then we had really sleepless nights.

[Narrator] What happens when a 145-year-old building

goes under the knife of an expert architect?

[Daniel] It's like a brain surgery.

You have to have the scalpel and all the precision instruments.

[Narrator] And how do engineers, building a 700-foot luxury

apartment block, face down a monster storm?

[Kevin] Unfortunately, we were at the worst part of the build

when that hurricane came.

[Narrator] This is the age of the extraordinary.

[Hayley] It's like one of those insect-eating plants,

only enormous and white.

[Narrator] Where ingenious engineers have

unleashed unchecked creativity.

Now their secrets are revealed.

As we discover the inside stories of their construction.

[Corina] This is an incredible feat

of planning and engineering.

[Narrator] To try and understand "How Did They Build That?"

To the beautiful mountains of Switzerland now

and a challenging and innovative construction project that really

puts the fun in funicular.

Do you even know what a funicular is?

No? Well, stick around.

With tunnels cut through solid rock,

and maximum gradients of 110%,

it's the world's steepest mountain railway.

Naturally, this being Switzerland,

the design is sweet as chocolate.

[Narrator] The Swiss Alps.

Home to 48 of Europe's highest peaks,

each over 13,000 feet tall,

it offers some of the continent's best winter

skiing and mountaineering.

Getting over 11 million people up the slopes here every year,

is a serious business involving 251 cable cars,

129 gondolas, and 42 funicular railways.

In 2012, more than 500 years after

the first funicular was built, work started on a new one.

It would cost $57 million and run two years overschedule,

but it also changed the face of the funicular forever.

[Hayley] You think, is it a train?

Is it an elevator?

In some ways, it's both.

[Narrator] The team had to tunnel through sheer rock

to create the steepest railway in the world.

And if that wasn't hard enough,

the carriages had to adjust to gradients from horizontal

to 110%.

[Corina] This thing has to go from dead flat

to nearly vertical without tipping over passengers

halfway up.

[Narrator] Capable of carrying 3,000 passengers an hour,

at speeds of 32 feet per second,

covering 2,500 feet of altitude in three minutes,

this is the Stoosbahn Funicular Railway.

So how did they build it?

The picturesque Swiss mountain village of Stoos

lies at an altitude of 4,000 feet

with stunning views over Lake Lucerne.

Like many Alpine villages,

it attracted wealthy Europeans in the 19th century.

But it wasn't until after the first world war,

when sports like tobogganing and downhill-skiing became popular,

the tourism really took off.

Mountain resorts needed efficient transport systems

up and down the steep slopes, in all weather.

And funicular railways were the perfect solution.

[Corina] The original Swiss funiculars of the 1900s

were powered by filling a tank in the car at the top

of the mountain with water.

Then gravity would bring it down to the bottom

and pull the bottom one up.

Simple, ingenious and sustainable.

[Narrator] Funicular railways solved the problem of carrying

passengers up steep slopes by pulling the carriages up

with a single cable, looped over a pulley at the top.

As one car descends, the other is pulled up at equal speed.

And because they're counterbalanced the pulley

only needs to lift the excess weight of the passengers,

which makes the whole system just incredibly efficient.

[Narrator] In 1933, the tiny village of Stoos

opened its first funicular,

which not only brought in the tourists,

but was also the main access into

and out of this car-free resort.

70 years later, the Alpine village wants to be better

connected to the valley below.

[Corina] Even if that means building the world's

steepest funicular railway.

[Narrator] One that will take the most direct route,

straight up the north face of the mountain.

It comes with some of the toughest terrain imaginable

in gradients of 110%.

[Corina] A 1% gradient means that if you move

100 feet forward, you're gonna gain one foot in elevation.

So a 110% gradient means that for every 100 feet you go,

you're goingn to be climbing upwards 110 feet.

So in other words, it's really, really steep.

[Narrator] To carry passengers up and down this mountain,

the engineers will need to design and build the steepest

funicular railway on the planet embracing some old-school

funicular tricks while coming up with some brand new ones.

The plan is for the new funicular to link Stoos

with the town of Schwyz in the valley below.

The route will climb 2,500 feet in altitude,

on a single track that's over a mile long.

Three tunnels will be carved through the mountain

at some of the steepest gradients ever attempted,

48 degrees.

At either end, bridges will connect the near

vertical mountain to horizontal station platforms.

And engineers will have to design revolutionary carriages

able to adjust to that using radical hydraulic engineering.

Reinventing a tried and tested transport system is one thing,

engineering and building it is another.

At the start, we tried to understand would it

be possible this steepness to manage?

Is it possible from a technical point of view?

And what would it cost about?

[Narrator] The first challenge Bruno and his team face

is excavating a straight route up the mountain.

In 2014, work begins on the first of three tunnels.

They turn to an innovative form of drilling originally used

to create ventilation shafts in mines called raise boring.

[Ellie] Raise boring is most often used where you have

to create a vertical tunnel.

First you drill downwards with a smaller pilot drill

until it emerges at the bottom, then to that you add a bigger

drill head and pull it back up, widening the hole.

The benefit is that your waste drops out of the bottom

of the hole on its own.

And that saves a lot of shoveling.

[Narrator] The team expects excavating the initial

10-inch pilot holes to take five days.

But part way through, the drill piece breaks

bringing the project to a halt.

The rock formation goes down and up on the other side.

But here it turns.

And in this area, it's very difficult.

Unfortunately, when they made the pilot hole

which was 25 centimeters, it was blocked.

And then we had really sleepless nights.

What's going on now? Then it was one year blocked.

That was really a very, very difficult situation.

[Narrator] The project is already a year behind schedule

and they haven't even started building the actual railway.

[Narrator] In Stoosbahn after a very, very long wait,

the drill bit needed to bore the funicular railway tunnels

is repaired.

Work restarts and the team hold their breath waiting

for the drill to break through the rockface at the bottom.

At the last day,

I saw the responsible machinery employee was very nervous.

And I ask him, why are you so nervous?

He says, blocked again.

No, no, no. Listen. Look, look, look, look.

And after five minutes came water, water, water out

of the of the wall, water.

And then came the rest out.

And it was really, it was like a baby's born.

[Narrator] A year behind schedule,

the team resumes excavating 30 feet of tunnel per week,

blasting the primary holes,

and enlarging them with a special boring machine,

before coating and sealing them with concrete.

This is precarious work.

For a lot of the time you're working in freezing conditions.

You might be on extreme slopes, and with the risk of rockfalls

or avalanches at any given time.

[Bruno]For the workers, they had,

sometimes we worked 24 hours a day.

That was a huge challenge to guarantee this safety.

[Narrator] Finally, in February 2017,

three tunnels totaling 1,900 ft. In length are finished.

The tunnels may be complete,

but the engineers' challenges are far from over.

Next, they need to create a carriage system that can handle

the extreme changes in gradient,

from steep mountain to flat station platform.

[Ellie] With most traditional funiculars the cars are raked

at a fixed angle, all the way from the bottom to the top.

But with this system they have to go from zero degrees

up to 48 degrees, and then back to zero degrees again.

[Narrator] The man charged with designing carriages

that can do that, is engineer Niklaus Moser.

The solution comes to him one night in his kitchen.

[Nicholas] I was at home, and of course, I was drinking a beer,

can of beer.

And uh, as time goes by, this can gets empty

and I just put it down and rotated it.

[Narrator] Nicholas's empty beer can inspires a futuristic,

barrel-like design for the carriages.

It will feature level-adjusting cabins

that are always horizontal,

however steep the dizzying incline.

A hydraulic piston within the chassis

continually rotates the cabins to remain horizontal,

so the 34 passengers in each pod can move around freely.

The exterior steel and glass shell means

they also enjoy unobstructed, panoramic views of the valley

and mountains.

And they say no good can come from drinking beer.

[Narrator] Five years after construction began,

the revolutionary Stoosbahn Funicular is almost operational.

The team has one final check,

stress testing the prototype carriage systems

at extreme gradients.

[Nicholas] We tested it.

We were rotating and do all the functional tests.

We lift it up in this 110% slope.

It was a very, very nervous time

and a very, very challenging time.

[Narrator] The radical funicular carriage system achieves what

many thought was impossible.

Under test conditions the interior barrel-like cabins

rotate horizontally at gradients of 110%,

and then back to zero again on the flats.

There were some small hiccups.

This is pretty normal, fine-tuning, et cetera.

Some modifications had to be done.

[Narrator] It's now time for the first test run

of both carriages at once.

Unlike the earliest funicular railways where the carriages

ran on two separate tracks, here, there's only one.

So how do they pass?

The narrowest system has both cars on the same tracks.

And they only split into two when they pass each other

at the midway point.

[Narrator] This very simple system was invented in 1879

by Swiss mechanical engineer, Carl Roman Abt.

At the heart of it is a wheel with two rims.

If this is fitted on the outside track

and wheels without rims are fitted on the inside,

when the track splits in two it guides the carriage onto the

right-hand track and then back.

[Nicholas] It pulls them out automatically to the outside

and guides them back in.

So that's called the Abt passing loop.

[Narrator] That's the theory, but in practice the first run

on a new track and passing loop is always a nervous time.

[Bruno] I had a dream that when first times both wagons

cross in the middle

that it would be not in the middle

and then I waked up.

[Narrator] The teams calculations of cable length

and tensioning are the difference between

the cars passing safely or colliding.

We had a little bit, we have been a little bit nervous

because it's a prototype.

But then when it happens first that both crossed in the middle,

it was in the middle, so that was a really exciting moment.

[Narrator] Against the odds, on December 17th, 2017,

the new Stoosbahn Funicular Railway opens to the public.

Two years overschedule and about 30 million dollars over budget,

the build may not have run quite like clockwork,

but within months Stoos, with its incredible new railway

is voted one of the top tourist destinations on the planet.

[music]

You want to build a tower, the most futuristic,

state-of-the-art residence in downtown Miami.

Its design will require one of the world's most

avant-garde architects to push the limits of what

even they think is possible.

You'll be using a concrete, glass-fiber hybrid

that's never been used in a project like this before.

Anything else?

Oh yeah, a hurricane is due to hit

right in the middle of construction.

So what do you do?

You get buildin', that's what.

[music]

[Narrator] Miami Florida,

where South Beach with its sun, sea and sand

has long been a playground for the super rich.

But there's a new kid on the block downtown

that's really turning heads.

Here, a clever developer with a visionary architect

came together and transformed the skyline

with an extraordinary 700-foot-tall tower.

They hoped it would send the price of property

up there with it.

[Corina] At up to 25 million bucks for an apartment,

this is definitely a place for the super rich.

[Narrator] But the stakes were high.

They were gambling on a radical inside-out structural idea,

never tried on this scale

They all thought we were crazy.

[Narrator] If that wasn't enough,

a major hurricane threatened the entire build.

I'm sometimes shocked that this was done.

[Joe] There was no turning back once we started

building this thing. We had to make it work

[Narrator] This tower named the 1000 Museum

forced engineers and architects on a journey into the unknown.

So how did they build it?

[Narrator] Miami's South Beach has long been a destination

synonymous with luxury.

A city known for its showing off,

houses here have sold for over $75 million.

Get it right with your developments,

you can make some serious money.

But in 2012,

land around South Beach is so eye-wateringly expensive,

that developers are looking elsewhere.

Kevin Venger thinks the time is right to bring that

million dollar price tag to a largely forgotten bit

of downtown Miami.

Better known for its museums than its luxury penthouses,

Kevin's got a dream of turning it into a new millionaires row.

Downtown, its location is in proximity to everything.

This site, has unparalleled views of South Beach,

the waters, the ocean.

[Narrator] So Kevin's plan is to build a residential tower block

and entice in the glitterati.

To do that, he decides on a skyscraper that's going to be

like nothing else on earth.

It's a huge gamble because if they don't come,

it could be financial ruin.

[Patrik] The ambition was to lift the market

on that side of Miami

and bring a kind of quality of architecture and lifestyle,

so that they can actually catch South Beach prices.

[Narrator] Right now though, Kevin has an ugly, one-acre plot

opposite Museum Park.

But he has a dream.

To make it a reality, he turns to Dame Zaha Hadid,

one of the world's most visionary architects,

whose extraordinary buildings from the Antwerp Port Authority

to the Quan Zu Opera House,

never fail to stop people in their tracks.

Here on the site of an old gas station,

she's going to have to work some serious magic

if she wants to wow the world

Zaha's designs around the world

are just so unique and different.

We knew we were going to have a really amazing tower

that was going to change the skyline in Miami forever.

[Narrator] Zaha and the team come up with a revolutionary

design solution,

creating a tower block that is strong enough

to survive Florida's hurricanes,

but also doesn't need the normal columns inside to hold it up.

It will start with building super-sized foundations

to support the building, even on the soft Floridian soil.

Then instead of the normal skeleton inside the tower

with concrete and steel columns giving strength,

the building will be wrapped in an exoskeleton of glass fiber

reinforced concrete.

This will allow uninterrupted spaces inside,

stunning views out, and the sharpest of finishes

appropriate for a block that comes complete with a helipad

for its uber-rich owners to pay a flying visit.

It has also, never been done like this before.

The design really gave us column-free

interior space.

With column-free interior space,

you can create amazing floor plans.

[Narrator] Zaha's radical designs have a reputation for

being notoriously hard to build.

And with an exoskeleton system that's never been tried before,

this one is going to be no exception.

[Luis] The first thing that popped into our heads is like,

yeah, we can make it work on paper,

but how are we going to build this?

Because traditional construction techniques

would not be appropriate for a structure like this.

No one had ever built anything like this before.

I knew this was going to be a

super challenging project, something nobody ever did.

I knew it was gonna be tough job.

I knew it was gonna be a long job.

[Narrator] In December 2014, work begins on site.

And the first challenge the engineers face

is laying the foundations for the 63-story tower.

The site itself, previously a gas station,

isn't huge

and butts up to its neighbours.

And unlike say New York where stick a spade in,

you're likely to hit granite,

here it's sandy soil for a long, long way down.

[Kevin] You have to be much more conscious about the settlement

of the project, so you don't have any issues

with your neighboring properties.

[Narrator] The team has to make sure that the

foundations will be solid,

and that the tower won't simply start sinking.

So the engineers decide to go deep.

[Luis] By going deeper, we would go into more

competent soil or rock,

which would end up minimizing the amount of settlement

that the building experienced.

They actually hit a record going 184 feet.

[Luis] The foundations ended up being the deepest foundations

that were ever done in Miami.

[Narrator] And the record breaking doesn't stop there,

because now they've found solid ground,

the next step is pouring the foundations,

an incredible 10,000 cubic yards of concrete,

which has to be done in one go.

It takes some serious organization.

But 24 hours later, the job is done.

[Luis] As that last truck is pulling away,

you get a sense of relief.

It's like, ah, okay, we're done.

No, but then reality kicks in.

It's like all we did was just set the foundation.

We still have 60 more floors to build.

[Narrator] And this is where the real

engineering challenge begins.

The developers want their high-end apartments

to go big on space

with virtually no internal columns.

To do this, the designers come up

with a ground-breaking, new exoskeleton that's

both strong enough to hold up the entire building

and beautiful without the need for any cladding.

[Corina] On a skyscraper, the concrete core in its center

provides its main structural support and stability.

The exoskeleton flips that idea on its head

because it gives that vital support

from the outside of the building.

Just like a scorpion or a cockroach,

that hard, outer shell holds its body together.

Its a win-win for developers because it means you can half

the size of the central structural core.

You use less concrete and you get to increase

the internal floor space.

Basically, you get more bang for your buck.

[Narrator] All good in theory, but how do you construct

a vast 700-foot-tall exoskeleton that can bear the weight

of the building, while showing off designer

Zaha's free-flowing curves?

There's only so many materials that you can use in order

to get that exoskeleton to achieve her design.

[Narrator] From the 15th floor up,

the curving exoskeleton becomes more intricate.

It needs to be built from something stronger,

so the skeleton can be thinner.

They hit upon an innovative material never before seen

on a US skyscraper called glass fiber reinforced concrete

or GFRC.

[Luis] You might ask yourself,

how is it that you're reinforcing concrete with glass?

Well, it has a high strength in tension,

so it starts to mimic the behavior of steel.

[Narrator] When you add fibers of glass to concrete,

not only do you get something that's super strong,

but also it can be formed into almost any shape imaginable.

Glass fiber reinforced concrete is essential for achieving

the clean, free-flowing curves that Zara Hadid is famous for.

Because it uses prefabricated panels,

you can get razor-sharp edges that you just can't get if

you're pouring concrete on site.

[Narrator] Normally, you create shapes in concrete by building

a mold called formwork made from something like plywood.

You fill it with steel-reinforced concrete

and when it's set, you take the formwork away.

But this new technique is literally a high-wire act

for the builders.

The mold is created from glass fiber reinforced concrete

that is also going to be the final exterior finish.

It should look stunning and be extraordinarily strong.

That's if everything goes to plan

because none of the construction crew has ever done anything

like this before.

I knew this was gonna be a challenge.

[Luis] The most nerve-wracking moment that we experienced

on the project is when we were going to see GFRC formwork

being used for the main structure of the building

for the first time anywhere.

[Narrator] With just half an inch of tolerance

built into the panels,

fitting them is going to be anything but straightforward.

[Kevin] They all thought we were crazy.

They said, oh, you guys are, this is crazy.

We're never gonna be able to handle the product.

We're never gonna be able to keep up with this.

This is a whole new thing.

It took a learning curve for sure.

[Patrik] I think the contractors were swearing against us,

you know, each panel took quite a while,

but it matters. It's really beautiful.

[Luis] That was a huge sense of relief

because we had 50 floors more of this to go.

[Narrator] Barely is the exoskeleton finished

before mother nature throws a very dangerous curveball.

In August 2017, Hurricane Irma is predicted to hit Miami.

Bad enough for a finished building.

Right now, it's potentially catastrophic.

Unfortunately, we were at the worst part of the build

when that hurricane came.

That's the real test for a building for a first time.

We had finishes going up the building in the lower floors,

glass going up in the middle floors

and the tower at the top, wide open.

[Joe] Cranes were getting taken down from this hurricane.

You know in a couple of locations,

actually pretty close to here.

It's a gut shot that you just hope that you just

have some water damage and some minor issues.

[music]

[Narrator] Next, Hurricane Irma makes landfall.

[Narrator] In Miami, the team are two thirds

of the way through building the 1000 Museum.

When on September 9, 2017, Hurricane Irma makes landfall.

Six-foot storm surges flood the coast.

Winds over 150 miles per hour batter the city.

It causes over $25 billion worth of damage across the Gulf.

But somehow, miraculously,

the 1,000 Museum building weathers the storm.

There was very little damage from that hurricane.

We got off lucky.

[Narrator] The team gets to work finishing the final floors

of the tower.

All of the earlier drama fades away under sunnier skies,

and the rest of the build comes off without a hitch.

After four and a half years of sweat and tears,

Zaha Hadid's visionary skyscraper is at last complete.

Outside, Miami's latest ultra-futuristic addition

transforms the city's skyline.

While inside, the exoskeleton has also done its job,

leaving uninterrupted eyelines and barely a column in sight.

The design sceptics thought it couldn't be done really is

and it's breathtaking.

All of the units have 10-foot high ceilings

and all glass wrapping around gives you right away

when you walk in water views

and a lot of light coming into your living room.

I love bringing people up here.

Seeing what we've achieved

here is a huge sense of accomplishment.

[Joe] This one is probably the best building

that I've ever built in my career in it

and the toughest.

[Patrik] The workers themselves, they loved the challenge.

It was a kind of bonding experience of,

creating something extraordinary.

I have an extreme sense of pride every time

I look at the Miami skyline.

1,000 Museum stands out like the pinnacle of

all the other high-rises.

There's nothing like it else in the world

[Narrator] A developer took a massive risk.

An architect pushed the boundaries,

and a construction team went the extra mile.

The 1,000 Museum is a true testament to how embracing

the revolutionary can build the extraordinary.

[music]

To Germany now where deconstructivism is transforming

the face of the historic city of Dresden.

In this case, a 135-year-old,

neo-classical palace and what appears to be

a crystal-shard rocketship falling from space.

The result, I am sure you will agree, is out of this world.

[Narrator] Built in 1876, this building has been an armory,

an Army museum, a Nazi museum

and a Soviet museum

before closing following the reunification of Germany.

Then 15 years later,

it rose like a phoenix from the ashes

to become one of the country's most extraordinary buildings.

This huge 21st century glass and steel arrowhead

seems to just penetrate this historic building.

[Narrator] An architect with an idea to transform

the traditional into something completely fresh.

[Daniel] It's like in a heart transplant.

You're changing the heart of a building.

[Narrator] Opened old wounds among the local population.

[Narrator] It took 15,000 tons of glass, concrete, and steel.

Some serious precision engineering

and seven years.

This is the Bundeswehr Museum of Military History.

So how did they build it?

[music]

[Narrator] Until World War Two, Dresden was considered

so splendid it was known as the jewel box.

Then in February 1945, the city was fire bombed by the allies.

25,000 inhabitants lost their lives

and little remained,

except, somewhat ironically,

the military museum, which was unscathed.

Following the war, Dresden was under Soviet control

and the museum was used to tell the story of warfare

from a Soviet perspective.

But with the fall of the Berlin Wall in 1989,

its mission became unclear and its doors were closed.

15 years later,

historians started to seek new ways to frame Germany's

dark, military past.

[Narrator] In 2001,

the city decides the old Dresden building

will become Germany's biggest and most important

military history museum,

but it needs a radical reinvention

to make it fit for purpose.

[music]

[Narrator] Next they have little idea how radically different

it's going to be.

[music]

[Narrator] In Germany,

plans are underway to create a museum,

which will tell its military history in a

radically, revamped building in the city of Dresden.

Architect, Daniel Liebskind is known for his daring approach

to sensitive projects,

such as Berlin's Jewish Museum

and the World Trade Center memorial site.

He pitches for the Dresden job.

[Ellie] To create a space that is appropriate

for the complexity and sometimes incredibly

dark history of Germany's military

is a monumental design task.

Daniel Liebskind is perhaps one of only a few

capable of taking this on.

[Narrator] As a Polish American of Jewish descent,

this project strikes a chord with Daniel.

What drew me to the project is the importance

of military history.

You know, all the wars, World War One, World War Two,

the millions of dead.

That's very interesting to address it,

to think about it and to create a building

that is contemporary and that speaks to that history.

[Narrator] Daniel's architectural vision

will strike at the heart of the old 19th-century institution.

The center of the building will be stripped back

and reinforced to prepare for what's to come.

A mega five story, 15,000 ton wedge of glass,

concrete and steel will cut through the

classic 135-year-old brick facade.

Inside this awesome extension, a gallery of new collections

will bring the story of Dresden up to date.

At its peak,

an 82-foot-high viewing platform will have breath-taking look out

onto the modern city and point to Dresden's tragic past.

People can enter through this new vector

and look at something so important,

which is where the first bomb that destroyed Dresden,

where did it land? Just in front of that wedge.

And the wedge itself a similar form to the two other

bombs that fell in the back.

So the triangle of bombing,

you're actually standing in it when you look at the new

horizon of Dresden.

[Narrator] Although not popular with everyone,

it's the design the city settles on.

[Narrator] When construction starts in 2004,

the first challenge is making sure the 128-year-old building

isn't destroyed by the new 15,000-ton addition.

[Ellie] Adding an extension is potentially fraught with danger.

Any new load bearing down on the existing building

could cause it to fracture and even crack.

It's hard to be sure how strong the foundations are,

how it was constructed.

It could have experienced settlement over the decades.

So you have to proceed with extreme caution.

[Narrator] Delicately, they slice away 15%

of the original building.

[Daniel] It's like a brain surgery.

You have to have the scalpel and all the precision instruments.

You have to know exactly where you're cutting

and what you're doing.

[Narrator] As well as carefully removing part of the building,

the engineers need to strengthen the foundations

where the new structure will be built.

[Narrator] A network of more than a hundred slimline

steel reinforced piles is sunk 10 feet under the building

ready for a huge new reinforced concrete slab to be laid on top.

The delicate, but incredibly strong foundation system

will support the new extension

without ruining the original 19th-century building.

Now they can turn their attention

to the extension's concrete shell

featuring 100-foot-high walls set at extraordinary angles.

[Narrator] The engineers use 3D computer modeling

to calculate how thick these great angled walls need to be.

Then they're built from reinforced concrete

while huge temporary steel beams hold the whole thing up.

[Narrator] The heavy new structure is carefully built

around the old stonework arches.

The building is at its most vulnerable since 1945.

It's like in a heart transplant where you hold a patient

on a machine pumping blood and air to the lungs

while you're changing the heart of a building.

[Narrator] That's not the only issue.

The team is struggling to get a concrete mix that will give

the walls the cast-iron strength they need.

[Narrator] Finally through trial and error,

they find the right recipe for the concrete.

The building goes up story by story

until finally the concrete roof goes on.

Now all that's left

is to create the imposing 100-foot steel exterior

with the awe-inspiring viewing platform

pointing towards Dresden.

It needs to protrude from the front of the old museum

without destabilizing the fragile 19th-century facade.

Using a master stroke of illusion,

the new addition barely touches the old.

[Narrator] The engineers wait nervously as the steel arrowhead

is hoisted into position.

[Daniel] I think the most nerve-wracking day was the day

of seeing the two forms

in complete integrity

speaking to each other.

I think that's really the moment where you hold your breath.

[Narrator] It's a big success,

as 21st-century steel meets 19th-century brick

and Libeskind's sketch becomes a living building.

[Narrator] After seven long years of construction,

the Bundeswehr Military Museum finally re-opens

to the people of Dresden.

[Narrator] Old is perfectly intwined with new,

and the added 330,000 square feet of exhibition space

finally meets Germany's difficult history head on.

[Daniel] I love that museum.

It's, you know, so precisely built.

It's so straight-forward, it speaks to everyone.

I want to make sure that people understand

what the stakes are for us human beings in this history.

[music]