In 1964 Teufelsberg – a hill rising up to 112 metres – is equipped with a ski lift and floodlights, creating Alpine-like conditions for skiers in the walled-in city. Berliners can take skiing courses free of charge. This urban winter sports location even features a ski jump. However, over the years, American agents working in the listening station on Teufelsberg claim that the skiers are disrupting their work. In 1999 the entire infrastructure is dismantled.