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 1,000 square metres (11,000 sq ft) and is 18 metres (59 ft) high; its walls are up to 3 metres (9.8 ft) 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.