One Canada Square is a skyscraper in Canary Wharf, London. It was the tallest building in the United Kingdom from 1990 to 2010, standing at 770 feet (235 m) above ground level and containing 50 storeys. In late 2010, it was surpassed by The Shard (completed in July 2012) which stands at 309.6 metres (1,016 ft).
More information on the Wikipedia page [1]. The website is [2].