Khrushchev and East German leader, Walter Ulbricht ordered the closure of the border between East and West Berlin.
East German police and soldiers sealed the most frequently used border crossings between East and West Berlin with barbed wire.
Soviet troops began to replace the wire with a concrete wall.
It not only ran through the centre of Berlin, but also wrapped around West Berlin, cutting it off from East Germany.
The Berlin Wall had watch-towers, anti-tank devices, ditches, barbed wire, guard dogs, powerful searchlights and minefields to prevent escapes.
The only legal way across the border was through checkpoints.