По периметру. Вот тут: http://www.berlinwall.itgo.com
кое-что есть.
After it was done the wall was 107 km long and 4 m high in most places. It was constructed with a concrete wall with a concrete tube placed on top. On the East Berlin side was a lighted control area. Anyone who reached this area were shot on sight, without warning. This is where most people were caught. Then moving away from the control area toward East Berlin was a deep trench to prevent vehicles from breaking through the wall. In front of this was a patrol track that had attack dogs, bunkers, and guard towers. Finally there was a second, smaller wall. In total the wall cut through 192 streets.