Now in BEV. This is a flak gun tower built by the Germans in WWII. "G-Tower remains empty. The entire north-east and half of the east machine gun platforms have been removed during 2007 including the connecting walkways due to deterioration. The tower itself has been reinforced with steel cables encircling the entire structure, 12 cables are located above the machine gun nests, 6 just below, and an additional 4 midway up the tower. The tower is home to thousands of pigeons which nest on every platform and opening. The west side of the structure is also used as a cellular communications tower."http://en.wikipedia.org/wiki/Flak_tower#Flakturm_VI_-_Stiftskaserne.2C_Vienna