This is a Tier 1 Blueprint / MegaStructure. 30 St Mary Axe, also known as the Gherkin and the Swiss Re Building, is a skyscraper in London's main financial district, the City of London, completed in December 2003 and opened on 28 April 2004. It is 180 metres (591 ft) tall, with 40 floors. Its erection symbolised the start of a new high-rise construction boom in London.