Teufelsberg by Steph Goralnick.
With a name meaning “devils’ mountain”, Teufelsberg is a fantastically decayed remnant of former West Berlin. Built atop a mountain of WWII rubble dumped upon the exploded remains of a subterranean Nazi military technical school, it served as a cold war spy station of the NSA. A bizarre geodesic wonderland designed for supersecret intelligence gathering, turned into a hauntingly weird playground for excellent photojaunts and exercises with your own echo.
Hey Steph! Good to see you pop up on my dashboard (with attribution!). Berlin looks awesome, and New York misses you.