High Quality Content by WIKIPEDIA articles! The Zoo flak tower, (German: Flakturm Tiergarten or the Zoo Bunker), was a fortified flak tower that existed in Berlin from 1941 to 1947. It was one of several flak towers that protected Berlin from Allied bomber raids. Its primary role was to protect the government building district of Berlin, as well as provide bunker space for civilians during attack. The Zoo tower also had a hospital facility.