The Bunker (also Reichsbahnbunker) in Berlin-Mitte is a listed air-raid shelter. Originally based on plans of the architect Karl Bonatz, it was constructed in 1943 by Nazi Germany to shelter up to 3,000 Reichsbahn train passengers. The square building has an area of 1000 m² and is 18 metres high; its walls are up to two metres thick. There are 120 rooms on five floors. In May 1945 the Red Army took the building and turned it into a prisoner-of-war camp. From 1949 it was used to store textiles and from 1957 as storage for dry and tropical fruit.
In the summer of 1992 it was turned into a hardcore techno club.Gabba, hard trance, house and breakbeat parties were held on four floors. However, after a raid in 1995 the events became more irregular. A further raid in 1996 placed severe building restrictions on the tenants, causing the club to close.
In 2001, real estate investor Nippon Development Corporation GmbH bought the building from the government. In 2002, it was the venue of the Berlin art festival "Insideout".Boros Collection
Christian Boros purchased the bunker for his private collection of contemporary art in 2003. He subsequently had architects Jens Casper and Petra Petersson convert the building into a 32,000-square-foot (3,000 m2) exhibition space and build a 4,800-square-foot (450 m2) glass-walled penthouse on the roof. The renovation work was finished in 2007. The first permanent exhibition opened in 2008, featuring selected sculptures, installations, and light and performance works by, among others, Olafur Eliasson, Elmgreen and Dragset, Robert Kusmirowski, Sarah Lucas, Tobias Rehberger, Anselm Reyle, Monika Sosnowska, Santiago Sierra, and Rirkrit Tiravanija.