The BT Tower is a tall cylinrical building in London, England. The tower is located at 60 Cleveland Street, Fitzrovia. It has been previously known as the Post Office Tower and the British Telecom Tower. The main structure is 177 metres (581 ft) tall, with a further section of aerial bringing the total height to 189 metres (620 ft). Contrary to popular belief, it is not the same as the BT Centre (the national headquarters of BT), which is located at 81 Newgate Street, London.