Teufelsberg is a man made hill on the western periphery of Berlin, built by the Americans at the end of World War 2. Created out of debris on Grunewald’s plateau, Teufelsberg became the city’s highest viewing point and a favorable location for military observation. Prior to establishing the first permanent buildings there in the very late 1950s, mobile American listening units used to drive to various other locales throughout West Berlin hoping to gain the best vantage point for listening to Soviet, East German and other Warsaw Pact nations military radio traffic. Due to the evident vantage point it could offer, a permanent listening station was then built on Teufelsberg, to be run by the National Security Agency until the fall of the Berlin wall. With the end of the Cold War, the listening station became redundant, it was closed down and its equipment removed. It remained a disused structure for over 10 years, to which followed another 10 years of negotiations between various property developers interested in purchasing the land around it, the possibility to create a spy museum and the final decision to classify the hill as forest in the land use plan of Berlin. Although the site remains private property, since 2004 local visitors as well as tourists regularly access it. A bright gallery of graffiti colours the walls of the three floors just beneath the listening domes. Broken glass, rusty wires and asbestos are some of the elements that compose the interior design of this place.