Ultimate High Ground: Inside Devil’s Hill (Main Radome) Teufelsberg (Devil’s Hill) is an abandoned American spy base built atop a WWII-era rubble pile and Nazi ruin. After the fall of the Berlin Wall, the NSA and CIA shuttered this hilltop listening post and moved elsewhere. Most of the original buildings remain, but the entropic effects of weather is accelerated by the thousands of urban explorers which trespass here nightly. This was taken inside the main radome (protective, geodesic dome), looking straight up.