Berlin Wall
The Berlin Wall was the result of a series of events after Berlin was split up into East and West after WWII. From 1961 until 1989 it was raised, starting off with some simple barbed wire and patrols and eventually being built up to two separate walls with sentries at strategic points. The wall was topped with barbed wire at one point which they discovered was ineffectual, and so a smooth rounded top was added and seemed to work a lot better. Anywhere from 125 (official figure) and 1245 (non-official) people were killed trying to flee. Up until recently it was denied that defectors would be shot. As recently as 2007, official documents were discovered which revealed that snipers had orders to kill any man, woman, or child trying to flee. Parts of the Wall can still be seen today at the East Side Gallery.