Berlin's trio of flak towers (and those in other German cities)  certainly had formidable firepower, but it is not clear that they were effective, either as a hazard or as a deterrent, to Allied bombers.  Equally, while the Allies did attempt to destroy them, the flak towers proved largely impervious to the munitions dropped on them - although the fact that only very heavy bombs (such as Tallboys), dropped from a very high level that seriously compromised accuracy, may have played its part.  On the plus side, these extraordinary reinforced-concrete fortresses provided refuge for many of Berlin's women and children in the final stage of the war.  Best regards, JR.

After a raid - Berlin Zoo flak tower, 1945.

"Air raid alert" atop the Berlin Zoo flak tower, 1944.  The complete, neat uniforms suggest strongly that this is a staged, "publicity" image.  The uniforms cannot, however, conceal the small stature and fresh faces of the flak crew involved.  By mid-1944 (really even earlier), Germany's domestic anti-aircraft crews were largely composed of adolescent boys; many died in the course of their service (the example of Heligoland  comes to mind).  Best regards, JR.

"Air raid alert" - Berlin Zoo flak tower.

A 1945 view of the Berlin Zoo flak tower and its environs.  The fact that the flak towers were, to some extent, special targets in the general context of carpet bombing made them difficult to live with for their immediate neighbours - unless they had actually fled inside the tower.  It is arguable that the annihilation by bombing of the historic Berlin Zoo was contributed to by the presence of the flak tower, which attracted additional and particularly heavy bombing.  On one occasion (in 1943) a bunker-busting bomb hit the Zoo's vintage, Indian/Burmese-style elephant house, killing eight elephants.  Another elephant - which had escaped in circumstances somewhat unclear, had to be shot later.  Best regards, JR.