Codenamed 17/5001, this secret bunker was one of the communist world's most advanced bunkers, built to protect the leaders of the former East Germany from a nuclear attack but it was never actually used.
The three-storey bunker was built in a forest 25km (16 miles) north-east of Berlin, near Wandlitz, where the the East German government was accommodated in a special colony. The bunker reaches a depth of 70m (230ft) below ground. 85,000 tonnes of concrete were used while a four metre thick 'blast cap' over the bunker was designed to protect from explosions above. Complex filters shielded the bunker's occupants from radioactive or biological agents.
Its submarine-like tunnels divided by heavy metal doors lead on to 170 rooms. It was fitted with a fountain, power generators, air conditioning and "springed" rooms able to cushion residents from detonations. Over
Its construction began in secret in 1978 and finished in 1983, It was intended to house the East Germany leader Erich Honecker who ruled the German Democratic Republic (GDR) for almost two decades and 400 staff. It is rumoured that Honecker himself visited the bunker only once and wasn't happy with its environment.
Although urban explorers had found a way to enter inside earlier, the bunker opened for the first time to the public and for only 3 months in 2008, with its walls now covered in mould and the decontamination chambers long-defunct.