The British Telecom Communication Tower was built to cater for the UK’s growing telecommunications requirements. Completed in 1964 and officially opened in 1966, it was the first purpose-built tower to transmit high frequency radio waves; today it relays broadcast, Internet, and telephone information around the world. At 625 feet, it was London’s tallest structure until One Canada Square in Canary Wharf was completed in 1990. The tower was declared a national monument by English Heritage in 2001 and it became a Grade II listed building in 2003.