in their assault on Berlin, found it difficult to inflict significant damage on the flak towers, even with some of the largest Soviet guns, such as the 203 mm M1931 howitzers. After the war, the demolition of the towers was often considered not feasible and many remain to this day, with some having been converted for alternative use. Design iterations Each flak tower complex consisted of: a G-Tower (German: Gefechtsturm) "Combat Tower", also known as the Gun Tower, Battery Tower or Large Flak Tower, and an L-Tower (German: Leitturm) "Lead Tower" also known as the Fire-control tower, command tower, listening bunker or small flak tower. Generation 1 The G-Towers were square and tall, usually armed with eight (four twin) 12.8 cm FlaK 40 and numerous 37 mm Flak and 32 (eight quadruple) 20mm Flakvierling guns. L-Towers were , usually armed with four quadruple 20 mm guns. Generation 2 G-Towers were , usually armed with eight (four twin) 128 mm guns and sixteen (four quadruple) 20 mm guns. L-Towers were , usually armed with forty (ten quadruple) 20 mm guns. Generation 3 The G-Towers were , usually armed with eight (four twin) 128 mm guns and thirty-two (eight quadruple) 20 mm guns. The evaluation of even larger Battery Towers was commissioned by Adolf Hitler. These would have been three times the size and firepower of flak towers. Towers Flakturm I – Zoo Tower - Berliner Zoo, Berlin The tower built near the Berlin Zoo was the first generation type and covered the government district. It was also used as a repository for artefacts from the Berlin museum. The occupants surrendered to Soviets on 30 April 1945. In 1947 the British blew up the G-Tower on the second attempt with several tons of explosives. The L-Tower was demolished first in July. Flakturm II – Friedrichshain, Berlin Friedrichshain (1st Generation) G-Tower was partially demolished after the war; one side remains visible. The tower was caught in low-level aerial footage of the ruined city in 1945. L-Tower was demolished after the war. Both towers were covered over and now appear to be natural hills in Volkspark Friedrichshain. The G-Tower, known as Mont Klamott (Rubble Mountain) in Berlin, was the inspiration for songs by singer-songwriter Wolf Biermann and the rock band Silly. Flakturm III – Humboldthain, Berlin The third of the first generation flak towers was built at Humboldthain. The G-Tower was partially demolished after