Humboldthain Flak Tower (Berlin)

 Second World War 1939-1945, ruins, surface-to-air missile site / sam

Part of Albert Speer's "Inner Ring of Defence" against air attacks during World War 2. Each of the four towers held massive anti-aircraft guns with numerous smaller gauge guns around the tower. After the war the Russian occupying forces (despite it technically being West Berlin) attempted to blow up the tower. Its walls are up to 3 metres thick and only half of it was destroyed. Although the park was previously flat, a man made hill is now constructed with rubble from the post war cleanup that was also used to fill the tower and piled around it. It is possible to walk up the hill and to the top of the two remaining towers, with a nice view over Berlin. The Flak tower has been partly cleaned out and is available for tours with the "Berlin Underground" club.