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
St Mary Axe may derive from a combination of the church dedicated to the Virgin Mary and a neighbouring tavern which prominently displayed a sign with an image of an axe, or simply from the church name itself, which may have come from the axes used by the Worshipful Company of Skinners, who were patrons. The sign of an axe is reported to have been present over the east end of the church. The street St Mary Axe is now most notable for the Baltic Exchange at No. 38, and the "Gherkin" at No. 30, a distinctively shaped skyscraper built on the site