The BT Tower is a grade II listed communications tower in Fitzrovia, London, England, owned by BT Group. It was also known as the GPO Tower and the Post Office Tower, and later officially renamed the Telecom Tower. The main structure is 581 feet high, with a further section of aerial rigging bringing the total height to 620 feet. Upon completion in 1964, it overtook the Millbank Tower as the tallest structure in London until 1980, when it was overtaken by the NatWest Tower.