I went to the Imperial War Museum a few days ago – sadly it’s largely under construction at the moment, but should re-open in Summer 2014, so I can go back. Outside the front entrance is a section of the Berlin Wall.
The side that faced the west:
The side that faced the east:
And the narrow divide between the east and the west:
Perhaps 6 inches of poorly made concrete and rebar, forcing a psychological chasm that seemed for such a very long time to be completely unbridgeable. It’s worth thinking about.