Fisk Tower - Marvel Super Heroes

Flak towers were large, above-ground, anti-aircraft gun blockhouse towers constructed by Nazi Germany. "Flak" is short for anti-aircraft gun in German: Flugabwehrkanone. There were eight flak tower complexes in the cities of Berlin (three), Hamburg (two), and Vienna (three) from 1940. Other cities that used flak towers included Stuttgart and Frankfurt. Smaller single-purpose flak towers were built at outlying German strongpoints, such as at Angers in France and Heligoland in Germany.