Where was Checkpoint Charlie?
Checkpoint Charlie (or "Checkpoint C") was the name given by the Western Allies to the best-known Berlin Wall crossing point between East Berlin and West Berlin, during the Cold War.
GDR leader Walter Ulbricht agitated and maneuvered to get the Soviet Union's permission to construct the Berlin Wall in 1961, to stop Eastern Bloc emigration westward through the Soviet border system, preventing escape across the city sector border from East Berlin to West Berlin. Checkpoint Charlie became a symbol of the Cold War, representing the separation of East and West. Soviet and American tanks briefly faced each other at the location during the Berlin Crisis of 1961.
Checkpoint Charlie was a crossing point in the Berlin Wall located at the junction of Friedrichstraße with Zimmerstraße and Mauerstraße (which for older historical reasons coincidentally means 'Wall Street'). It is in the Friedrichstadt neighborhood. Checkpoint Charlie was designated as the single crossing point (by foot or by car) for foreigners and members of the Allied forces. (Members of the Allied forces were not allowed to use the other sector crossing point designated for use by foreigners, the Friedrichstraße railway station).
Alexanderplatz and Potsdamerplatz were not border posts. Glienicker Brücke, Potsdam was a bridge that was often used for spy swaps.