The Cold War sights of central Berlin are well-known (Checkpoint Charlie etc) but more interesting for me are the more mundane manifestations of the wall on the periphery of the city. West Berlin was an island of territory belonging to West Germany that was situated in East Germany. But around the edge of West Berlin there were also other tiny exclaves of western territory that East Germany put walls around. One of them is below. It's a weekend cottage settlement located on the East German side of the Heiligensee lake but belonging to the West German side on the other bank. To get to their waterside huts the West Berliners had to go through the full border control palaver. There is a wonderful 1970s archive photo on an info panel nearby showing a hippy Western couple with a barrow of garden provisions pressing the doorbell of a hatch in the wall, waiting to be let through by a no doubt shaven-headed border patrol officer. There were similar quirks in the border all around the city, including special transit routes for West Berlin to dump its rubbish on land leased from the East.