In this episode we travelled to France to visit the Maginot bunkers.
This is a huge tunnel system which was built between the two world wars. It costed 1,5 billion euro's.
We arrived at one of the many bunkers.
We only have to search for an entrance.
It's spreaded miles under the ground, this one is probably partly on a field and partly in a forest.
I've read that it's the biggest defence system in the world after the great wall in China, which is pretty impressive.
That's really deep ! Maybe 20 meters?
-I see bars so it's not an entrance.
I'm afraid it's closed.
We saw this from above. It's closed with bars.
-A deep trench.
We have many options right?
-Well it's all the same as this.
It's cool.
That's the difficult part of bunkers, it's easy to find them, but getting in is another story.
Same with prisons.
-But prisons are compact, bunkers are widely spread.
This one is on a field, so easy to spot. It's more difficult in the forest. You also have to be lucky it's open.
The army closed the entries, they don't want anyone to go inside, which I can imagine.
It's not obvious, you wouldn't expect bunkers here when you drive.
I should check the map if we are close.
O, check.
It suddenly appears.
That's recently closed.
-That was my old entrance.
I think there's another entrance.
-O, cool.
We're inside.
Deep.
Fkkng deep.
-An elevator shaft.
Throw a rock in there.
1-2-3.
3 seconds.
We go down?
-Yes.
There's a lot of water.
We're at the lowest point now and here you see an old train cart.
They were used to move the supplies.
Ammunition.
-And soldiers to the other bunkers in this tunnelsystem.
The train tracks are covered in mud, so you can't see them. You could see them upstairs.
It's a cool system.
And this tunnel is at least 1 mile long.
-Shut up I thought we were already there.
Jesus.
You can see the train tracks.
The funny thing is when you look at the map and wonder how large it is. You can't put it in a perspective.
But we're walking now for 10-15 minutes and maybe walked 10% of 1 tunnel.
That's a good indication how immense it is.
-Unbelievable.
And you can see the water flowing through the train tracks.
So there's a difference in elevation.
I think the barracks are to the right here. 
We can check it, but I guess it's emptied.
A toilet.
-That's it?
This is also on the tracks. No clue what it is.
A mobile generator?
I see a volt gauge.
Do we go back?
-No this way.
Won't we get lost?
No. we'll be fine.
Here you see a cast iron rail system.
So not only transport on the floor.
It's in a remarkably good shape, no peeling paint.
It's not in the water.
In case the enemy got inside the bunker, there are several security posts.
What a big door, check how thick it is.
Bizarre rooms.
Showers.
The actual showers have been removed.
There supposed to be taps there.
Fungus.
A bathtub, probably only for the higher rankings.
-The officers.
It's sick that this was built in just a few years.
-4, 5 years?
I think from 1930 untill 1938.
Check.
So in this bunker were between 500 and 1000 people.
Most bunkbeds are gone, but they slept in rooms like this.
There supposed to be beds higher on the wall.
Oil supplies.
Sinks.
Some bunkers were modernized during the cold war and some didn't. I think this hasn't been updated.
You can see how humid it is here.
-Crazy.
We're halfway in the tunnel...
and we found a workshop.
-An old machine.
It's a turning lathe right?
-I think so.
Pretty heavy.
There's a frog here, still alive.
My god.
Easy to navigate. Bunker 6.
High water.
My feet are completely wet.
And we left the waders in the car.
-Do you wanna go?
Yeah, your shoes are wet already.
This is all flooded. The water is so clear it's difficult to see.
I gonna throw a rock inside the water to show you.
Crazy.
This is a cool door.
Here was ammunition stored.
Locked behind bars.
Big rooms.
The staircase is covered in chalk.
-This leads to a turret? Yes.
Check the structure.
We're at one of the turrets in bunker 6.
We have walked a lot of steps going up.
-A crazy amount, comparable with a church tower.
Endless.
I think it's about 50 meters. (165 ft)
So now we have a little break.
-So we were really deep below the surface.
It's immense.
The main tunnel is 1 mile long, because they were still able to supply in case of a close combat.
And this is one of the spaces where you could find turrets.
In this room there was a huge turret.
And when you look outside you can see the forest.
It's cool to see it in real life.
Daylight.
-We haven't seen that in a while, we're walking around for 2 hours now.
Non-stop. It's the first break.
We should show you the pedometer.
And this is just 1 Maginot bunker, there's so much to see.
-This one has 6 bunkers with domes.
They are connected by the tunnel system.
They are marked in the tunnels.
But you still have to take a good look to find the staircase.
But there are more interesting parts to see where you can see the machine parts of the turrets.
It's a cool experience, it's so big.
Even when it's empty, it's impressive.
How did they build this in such a short time?
1930 untill 1938.
Hundreds of miles.
Imagine, covering the whole North-Eastern side of France.
From the swiss border.
-Defence was a big priority.
And they built it during an economical crisis, after WWI when France suffered a lot. Crazy project.
Time to continue.
-Just a second.
Here there was a anti-aircraft gun.
We know some bunkers where the equipment is still standing.
We'll go there when we have 500.000 views.
That one is further right?
-Way further.
A cool cart. Looks like a coal cart.
-It looks like one.
It's pretty big.
-What was inside?
No clue,  maybe fuel or oil.
Everything has the same style.
A walkway and all the rooms have the same ceilings.
One of the only doors which isn't totally rusted.
Here we go again. My god.
We're in bunker 2.
We're probably looking at the chassis of an anti-aircraft gun. It covers multiple floors.
This was heavy duty compared to the other equipment.
Another dome.
There were also turrets on this platform.
It worked like an elevator.
Let's find the others.
The highest point is probably an observation dome.
It still holds my weight after all those years.
Not much to see.
-Just a small opening.
Just a small soldier post.
That's it.
And the Germans never came.
That's the funny part of it.
The French thought they were clever but after 3 days the Germans already broke through the barrier.
Because they did a "blitzkrieg" through Luxumbourg and Belgium.
Through the North.
-So here they stationed all the best soldiers and in the North some older soldiers.
One of the many murals.
Some navy drawings, a boat scene.
Where you look through a window of a boat.
Here you can see turbines which provided the electricity in the bunker.
Stripped by copperthieves. In some bunkers they are in a better shape.
It doesn't smell healthy here.
-You can smell the fuel and oil.
-Still well lubricated.
Thre's only one gauge left.
Fuse boxes.
