Trump is waffling on the wall.

[abaris]

How did it go over mountains and stuff?

It didn't need to. Coastal patrol were all that's needed to secure the shores and mostly impenetrable mountains didn't need much of it either. But everywhere else it was at least layers of fences and barbed wire, mine fields and even shot systems. And light systems, lots of them.

I remember one night spent at a Hotel of the german city of Fulda. In 1979, I believe. The rotating searchlights from the border were that strong that I had a hard time finding any sleep.