Teufelsberg is a man-made hill in Berlin, Germany, in the Grunewald locality of former West Berlin. It rises about eighty meters above the surrounding Teltow plateau, north of Berlin's Grunewald Forest. The hill is made of rubble and covers an under-construction Nazi military-technical college (Wehrtechnische Fakultät). During the Cold War, there was a U.S. listening station on the hill, Field Station Berlin.