Flak Tower Humboldthain

The DCA Towers(German: Flaktürme) were eight anti-aircraft tower complexes of the blockhaus type built in the cities of Berlin, Hamburg and Vienna from 1940 onwards. They were used by the Flak of the Luftwaffe to defend against Allied air raids on these three cities during the World War II. They also served as air-raid shelters for tens of thousands of people and to coordinate anti-aircraft defense.
Source Wikipedia

The DCA Towers(German: Flaktürme) were eight anti-aircraft tower complexes of the blockhaus type built in the cities of Berlin, Hamburg and Vienna from 1940 onwards. They were used by the Flak of the Luftwaffe to defend against Allied air raids on these three cities during the World War II. They also served as air-raid shelters for tens of thousands of people and to coordinate anti-aircraft defense. Source Wikipedia