I can't find accurate data on this. I assumed that the Berlin wall seperated West Berlin from the rest of East Germany, because East Berlin itself is also East Germany and thus doesn't need a wall to seperate it from the rest of East Germany.
Yes and no. The Wall was an actual physical wall that surrounded all of West Berlin- as this map visualizes. But it was not just a simple wall. There were several checkpoints, the most famous being Checkpoint Charlie. There Wall also had a "death strip" of varying size on the East Berlin side of the Wall, as seen in this photo and partially in this GDR map. This strip was bare of municipal development and acted as an inner barrier between the Wall and East Berlin. This inner wall contained barbed wire, vehicle barriers, anti-personnel weapons, and guardtowers, all of which were a further disincentive for East Germans to try and scale the concrete wall. The ubiquitous ferroconcrete Wall itself was the last line of defense in the "anti-fascist defensive rampart" (the official name of the Wall). So the Wall itself was part of a larger network designed to make an escape to West Berlin a highly dangerous undertaking.
