Houses of Parliament, St. Stephen's Hall (Interior Mouse Mat
The Palace of Westminster, also known as the Houses of Parliament or Westminster Palace, in London is where the two Houses of the Parliament of the United Kingdom (the House of Lords and the House of Commons) meet to conduct their business. The Palace lies on the north bank of the River Thames in the London borough of the City of Westminster, close by other government buildings in Whitehall. The palace is one of the largest Parliaments in the world. The layout of the Palace is intricate, with its existing buildings containing nearly 1,200 rooms, 100 staircases and well over 3 kilometres (2 miles) of corridors. Although mainly dating from the 19th century, among the original historic buildings is Westminster Hall, used nowadays for major public ceremonial events such as lyings in state, and the Jewel Tower. Control of the Palace of Westminster and its precincts was for centuries exercised by the Queen's representative, the Lord Great Chamberlain. By agreement with the Crown, control passed to the two Houses in 1965. Certain ceremonial rooms continue to be controlled by the Lord Great Chamberlain. After a fire in 1834, the present Houses of Parliament were built over the next 30 years. They were the work of the architect Sir Charles Barry (1795-1860) and his assistant Augustus Welby Pugin (1812-52). The design incorporated Westminster Hall and the remains of St Stephen's Chapel.