The Teufelsberg is an artificial hill with a height of 120m in the West of Berlin. It consists of debris and rubble from the buildings destroyed during World War 2. The rubble was heaped on top of the military technical college which was never completed. By 1972 roughly a third of all the rubble ended up there. In the 1960ies the hill featured a ski slope with ski lift which was abandoned because the nearby American Cold War listening post wanted to be left alone.
Until the fall of the Wall, American and British security services operated the various antennas covered by the radomes. During the 90ies the site was used for civilian air traffic control. In the early 2000s there was a plan to build a conference centre, hotel and (no surprise) luxury flats. This scheme failed due to protests and exploding costs. The building work was abandoned.
Currently the site is full of fantastic graffiti and street art and can be visited.