--The flak tower is a high-rise reinforced concrete air defense facility built by the German Air Force during World War II as an urban air defense facility to protect strategically important cities from Allied air raids.
――The flak tower consisted of a G tower equipped with anti-aircraft guns and a command tower called the L tower equipped with radar and anti-aircraft command equipment.
――After the war, various equipment such as weapons were removed, and the flak tower itself was dismantled and removed, but many of them still exist and are being diverted to various purposes.

[Flack Tower I Berlin Zoo Tower]
--The first generation flak tower built in Berlin in April 1941.
――It was called the zoo tower because of the place where it was built.
--Destroyed by British troops at the end of the war.