Teufelsberg, known as Devil's Mountain, rises from Berlin's landscape as a peculiar blend of history and art. Built from wartime rubble, this 80-meter mound offers panoramic views across the city and stands on the remnants of a Nazi military college. During the Cold War, its strategic height proved ideal for U.S. spies, who, alongside British and French allies, erected antennas to monitor Soviet and East German communications. William McGowan, a former American soldier, recalls the intense surveillance efforts aimed at providing Western Europe with crucial warnings against potential attacks. Now abandoned, Teufelsberg has found new life under a collective of artists. The site, with its graffiti-covered halls, tells the story of transformation, being repurposed from a Cold War espionage hub to a vibrant gallery of street art.