City Hall is the headquarters of the Greater London Authority (GLA), which comprises the Mayor of London and the London Assembly. It is located in Southwark, on the south bank of the River Thames near Tower Bridge. It was opened in July 2002, two years after the Greater London Authority was created. The building has an unusual, bulbous shape, purportedly intended to reduce its surface area and thus improve energy efficiency, although the excess energy consumption caused by the exclusive use of glass (in a double facade) overwhelms the benefit of shape.