Gefechtsturm is a Flak towers (Flaktürme) were eight complexes of large, above-ground, anti-aircraft gun blockhouse towers constructed by Nazi Germany in the cities of Berlin, Hamburg, and Vienna from 1940 onwards. The towers were used by the Luftwaffe to defend against Allied air raids against these cities during World War II. They also served as air-raid shelters for tens of thousands of local civilians.
In Vienna military authorities chose the Augarten as one of several places to erect massive buildings for anti-aircraft defence to protect the inner city from Allied bombing. During summer 1944 the construction of a 55 metre high tower with platforms for anti-aircraft guns and nearby also a 51 metre high control tower was begun but not finished. Their remains are still visible in the middle of the park.
