30 St Mary Axe (known previously as the Swiss Re Building), informally known as The Gherkin, is a commercial skyscraper in London’s primary financial district, the City of London. It was completed in December 2003 and opened in April 2004. With 41 floors, it is 180 metres (591 ft) tall and stands on the former sites of the Baltic Exchange and Chamber of Shipping, which were extensively damaged in 1992 in the Baltic Exchange bombing by a device placed by the Provisional IRA in St Mary Axe, a narrow street leading north from Leadenhall Street.
After plans to build the 92-storey Millennium Tower were dropped, 30 St Mary Axe was designed by Norman Foster and Arup Group. It was erected by Skanska; construction started in 2001.
The building has become a recognisable landmark of London, and it is one of the city’s most widely recognised examples of contemporary architecture.
The building stands on the former site of the Baltic Exchange (24-28 St Mary Axe), which was the headquarters of a global marketplace for shipping freight contracts and also soft commodities, and the Chamber of Shipping (30-32 St Mary Axe). On 10 April 1992, the Provisional IRA detonated a bomb close to the Exchange, causing extensive damage to the historic building and neighbouring structures.
The United Kingdom government’s statutory adviser on the historic environment, English Heritage, and the City of London’s governing body, the City of London Corporation, were keen that any redevelopment must restore the Baltic Exchange’s old fa?ade onto St Mary Axe. The Exchange Hall was a celebrated fixture of the shipping market.