Including this for the irony. This was built during the 1930’s, for a staggering cost of 3 billion Francs ($3.7 billion dollars today.) It was a series of obstacles, fortifications and weapons stretching along the France’s borders with Italy, Switzerland, Germany and Luxembourg. The plan was to deter Nazi troops.

Except, they forgot about the Ardennes forest, where they figured the terrain was too tough for the Germans. It wasn’t. They invaded in 1940 and occupied the country.