Flakturm IV or Flak Tower IV, a former Nazi bunker in Germany, will now be turned into a luxury hotel. In response to Berlin air-raids by Allied Forces in 1940, the Nazi regime issued an immediate decree to build air-raid shelters in cities all across the Third Reich. The Hochbunker in the St Pauli district of Hamburg was built during World War II and was one of two towers created by the Nazi&rsquos for air defense during the war.

The bunker was constructed in 300 days by over 1000 forced labourers and was used to launch anti aircraft fire at allied planes. It was designed to accommodate 18,000 people and featured a special, extra-wide entrance for women with prams and children. During the air raids on Hamburg in the summer of 1943, about 25,000 people sought shelter in the bunker and were well-protected by its thick walls. The bunker has been in constant use since then. Initially civilians were accommodated in the building during Germany's postwar housing crisis. Later, the space was used by a German TV station and other businesses. Since the 1990s, the bunker came to be known as "media bunker," housing around 40 organisations including nightclubs, radio stations and studios.

The new hotel, apart from featuring spaces for culture, exhibitions and a hall for sports and entertainment events, will offer 136 rooms and a bar, a coffee shop and a restaurant. It will have five levels in the shape of a pyramid, including a spectacular roof-top garden. There is also talks of a memorial there. The opening is planned for mid-2021.

At the end of WWII, Hamburg had 1,051 bunkers &mdash more than any other German city. Currently, there are still some 650 bunkers left most of which are more discreet.