Nazi Megastructures

Berlin,

the capital of Nazi Germany and Hitler's power base,

a gleaming city at the heart of the Fuehrer's plan

for an empire to outshine the Romans.

Adolf Hitler fancied himself as an architect.

But then the Russians arrive

and Hitler must prepare Berlin for battle.

It was all about elevating

the most powerful cannons above the city rooftops.

The city becomes a fortress.

Buried at its center, the indestructible Fuehrerbunker.

This is where Hitler's going to make his last stand.

One million Russian soldiers,

five layers of Nazi defenses

and a battle to decide the future of the world.

This is the story of Fortress Berlin.

The biggest construction projects of World War II,

ordered by Hitler to secure world domination.

Now they survive as dark reminders

of the Fuehrer's fanatical military ambitions.

These are the secrets of the Nazi megastructures.

April the 28, 1945,

the tanks of the Soviet Red Army

roll through the streets of war-torn Berlin.

German troops, many just children,

lie in wait to defend their city from the Russian hordes.

18-year-old soldier Dieter Borkowski

will be an eyewitness to these unfolding events.

All over the city are haunting reminders

of these last days of the Nazi capital.

Historian and World War II expert Michael Dempsey

has spent years piecing together the evidence.

The Battle of Berlin was of a scale we can scarcely imagine.

Over a million Soviet Red Army soldiers are entering the city,

less than 100,000 are defending it.

The scale, the intensity, the brutality

of this Battle of Berlin would beggar belief,

but for the evidence.

Just ten years earlier in 1935,

the picture was very different.

Berlin was the seat of Nazi power,

a cosmopolitan world city

and one of the cultural capitals of Europe.

Hitler and his chief architect, Albert Speer,

had embarked on an ambitious construction program

to transform the skyline of Berlin.

Adolf Hitler always fancied himself

as something of an artist, as perhaps an architect,

a man with high cultural pretension.

Colossal government buildings,

airports and stadiums

all showcased at the 1936 Olympic Games.

Hitler had even greater plans for the capital,

to make it the center of a thousand-year Reich

that would match the Roman Empire in scale and longevity.

Hitler's new created Berlin with its vast domes,

huge streets, massive, giant outsize edifices,

this is very much part of the German psyche.

Hitler lays the foundation

for his thousand-year Reich

by conquering large swathes of Europe.

But in 1944, British and American troops land

on the French coast and advance from the West.

In the East, the Russians push back from Stalingrad,

until they cross the frozen River Oder,

bringing them to within 48 kilometers of Berlin and Hitler.

The Allies are on the verge of ending World War II in Europe.

The battle along this river could decide the fate of Germany.

All the weapons you have are the last we have,

you must fight fanatically to stop the Russian offensive.

Hitler will never surrender.

He's a man of extremes, so it's the thousand-year Reich

or it's collapsing in Armageddon. There's no middle ground.

It's always one or the other in his mind.

The Fuehrer clings to the hope

that one of his wonder weapons

might yet turn the war back in his favor.

To buy time, he holds out in Berlin,

creating a castle of concrete and steel

and ordering every last German to defend it to the death.

Berlin, of course, is going to become a fortress

because it's the capital of the Third Reich.

This is where Hitler's going to make his last stand.

Hitler's plan is to encircle Berlin

in five layers of formidable structures,

starting with the first obstacle,

59 kilometers of tank traps at Seelow Heights.

An outer ring of defense including the Teltow Canal,

an inner ring at the stronghold of Tempelhof Airport,

three enormous flak towers,

a final layer of waterways

and the core of the Fortress, the Citadel.

It is here that the Reichstag and Hitler's bunker are located.

This is a car park in the middle of Berlin,

probably the most interesting car park in the world,

given that it is the authentic historical site of Hitler's bunker.

8 meters beneath this car park

are the remains of the infamous Fuehrer bunker.

After the war, the Allies tried to demolish it

to prevent it becoming a Nazi shrine, but it was too strong.

It wasn't until 1988 that the lid of that concrete case

was actually destroyed over a 6-month period.

The story of its construction

and the start of Fortress Berlin

begins with Allied bombing raids over the capital.

The Fuehrer no longer feels safe.

From the outset, Hitler has always been a bit obsessed

with being underground.

It goes back to his experiences in the trenches in the First World War.

You find a lot of people who've lived through the First World War,

they feel secure underground.

The Nazis bury the Fuehrerbunker

deep beneath the chancellery gardens.

There are 30 small rooms distributed over 2 levels

and Hitler's room is in the deepest section

with the most protection.

25 miles south of Berlin, in the town of Zossen,

are the remains of another Nazi complex

that gives a unique insight into Hitler's bunker.

Former armored squadron leader Nigel Dunkley

is an expert in the fall of Berlin.

Right, here we are in the Zossen Wunsdorf bunker complex.

This bunker complex was built by the same company

that also built Hitler's bunker,

so it's the last thing that we've got anywhere near or in Berlin,

which is pretty well identical

in construction and in atmosphere to Hitler's bunker.

These bunkers cover an area

of nearly 5,000 square meters.

It was the German military communication nerve center,

the Nazi equivalent of the Pentagon.

To protect it from Allied air attack,

the engineers didn't just bury it 11 meters below ground.

They also gave it an impenetrable roof,

something Hitler wanted in his bunker, too.

This is 3 meters of reinforced concrete,

reinforced with steel rods.

Now, over Hitler's bunker,

he had 4.5 meters of reinforced concrete

designed to protect him from anything

that either the Soviets or anybody else could throw at him.

Hitler's bunker is in the middle of the fortress.

Like a castle, it is surrounded with water.

The river Spree and the Landwehr Canal

encircle the Citadel in a natural moat.

The next layer is the three flak towers,

fortresses 15 meters high,

each bristling with 20 anti-aircraft weapons.

Only one still exists

and access to its extraordinary interior is limited.

Local guide Sion Davies is an expert on their construction.

We're standing on the only side of the building

that still survives, the north face of the flak tower

and it really gives us an idea of the scale of the building.

These flak towers will soon become

the most important defensive structures in the whole of Berlin.

But they get their start

when Allied forces begin to bomb the city.

The first British bombing raid

found Berlin relatively lightly protected.

The reason is very simple,

the Nazis had traditionally not thought

that the British and indeed any other Air Force

would successfully bomb Germany.

Hitler needs to protect Berlin,

to preserve it for its future as the capital of his Empire.

The Nazis immediately embarked on a building program

to create air-raid shelters and fortresses to protect the cities

from future bombing raids

and that's what Hitler was involved in.

The flak-tower design is Hitler's brain-child

and he employs his favorite architect

to oversee the project, Albert Speer.

This is how I see the new flak towers.

Are they a viable design?

Of course, they are impregnable,

and they will be guarding this new fabulous city of ours for centuries.

Good.

Well, Albert Speer is a very interesting character

because he's an architect and he buys into Hitler

and he buys into what the Nazis represent,

but he's a hugely capable, clever, highly motivated individual.

Hitler's design requires over 100,000 tons

of tough concrete and steel.

Every day 3,700 tons is shipped to the capital

just to build the flak towers.

The railway timetable is changed to accommodate

a never-ending stream of material.

Despite their scale, each of these bastions of Fortress Berlin

are constructed in just eight months.

The flak tower was all about elevating

the most powerful cannons in the German arsenal

above the city rooftops, giving them a perfect field of fire.

The square tower has four turrets,

each with dual 128mm flak guns,

powerful weapons designed to bring down Allied bombers.

But when the Russians arrive,

these guns will be pointed down the streets.

One of the soldiers tasked with manning

these flak-tower guns is 18-year-old Dieter Borkowski,