Home to the Mayor of London, bulbous City Hall was designed by Foster and Partners and opened in 2002. The 45m, glass-clad building has been compared to a host of objects – from an onion, to Darth Vader’s helmet, a woodlouse and a ‘glass gonad’. Excellent green credentials include the use of cold ground water for its air conditioning system. The scoop amphitheatre outside the building is the venue for a variety of free entertainment in warmer weather, from music to theatre. Free exhibitions relating to London are also periodically held at City Hall.