Houses of Parliament

Houses of Parliament, also New Palace of Westminster, seat of the British legislature, a great mass of buildings on the north bank of the River Thames in London. It was built (1840-1870) after plans by Sir Charles Barry, on the site of the medieval royal residence, the Palace of Westminster, which was largely destroyed by fire in 1834. The buildings cover an area of more than 3 hectares (8 acres) and contain 1,100 apartments, 100 staircases, and 11 courts. The exterior, in rich late Gothic style, is impressive with its three massive towers: Victoria Tower (102 m/336 ft), Middle Tower (91 m/300 ft), and St Stephen's, or the Clock Tower (98 m/320 ft). The latter contains a clock with four dials, each 7 m (23 ft) in diameter, and a great bell, Big Ben, weighing 13.8 tonnes. Among the houses are the sumptuous House of Lords; House of Commons; St Stephen's Hall on the site of St Stephen's Chapel; the residence of the Speaker; the libraries, committee rooms, and lobbies connected with the House of Commons and the House of Lords; and offices. Westminster Hall (begun 1097) is all that remains of the original palace.

During World War II the buildings were seriously damaged in air raids. In 1974 a bomb planted by Irish nationalists slightly damaged Westminster Hall and destroyed an annexe to it. The complex was designated a UNESCO World Heritage Site in 1987. See Parliament.