The ruined spy base with a hidden past

On top of a hill called ‘Devil’s Mountain’ in Berlin, there’s a graffiti-coated former listening station that once spied on the Soviets. BBC Future looks inside the derelict structure, and speaks to the people who worked there on the day the world almost plunged into accidental nuclear war.

Join 800,000+ Future fans by liking us on Facebook, or follow us on Twitter.

If you liked this story, sign up for the weekly features newsletter, called “If You Only Read 6 Things This Week”. A handpicked selection of stories from BBC Future, Earth, Culture, Capital, and Travel, delivered to your inbox every Friday.