a very tall tower in central London which is a well-known landmark. It is 191 metres high and was completed in 1966. It is a communications centre for telephone, television and radio communications. It was originally called the Post Office Tower until the Post Office and British Telecom (now BT) became separate organizations. It has also been known as the Telecom Tower. There was originally a restaurant at the top of the Tower which moved round continuously and gave excellent views over London, but this was closed in 1971 after a bomb attack on the Tower.