30 St Mary Axe nearly oblivious to the tower's existence until directly underneath it. The building was constructed by Skanska, completed in December 2003 and opened on 28 April 2004. The primary occupant of the building is Swiss Re, a global reinsurance company, which had the building commissioned as the head office for its UK operation. The tower is thus sometimes known as the Swiss Re Building, although this name has never been official and has more recently fallen out of favour, since the company's main headquarters is in Zurich and the Gherkin name has become more popular. The building uses energy-saving methods which
30 St Mary Axe designed by Norman Foster and Arup Group. It was erected by Skanska; construction started in 2001. The building has become a recognisable feature of London, and it is one of the city's most widely recognised examples of contemporary architecture. The building stands on the former sites 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