What do you know about Big Ben and the Tower of

Big Ben is the nickname for the Great Bell of the clock at the north end of the Palace of Westminster in London, and often extended to refer to the clock and the clock tower. The tower is officially known as the Elizabeth Tower, renamed as such to celebrate the Diamond Jubilee of Elizabeth II. The tower holds the largest four-faced chiming clock in the world and is the third-tallest free-standing clock tower. The tower was completed in 1858 and had its 150th anniversary on 31 May 2009, during which celebratory events took place.
Tower of London, is a historic castle located on the north bank of the River Thames in central London. It lies within the London Borough of Tower Hamlets, separated from the eastern edge of the square mile of the City of London by the open space known as Tower Hill. It was founded towards the end of 1066 as part of the Norman Conquest of England. The White Tower, which gives the entire castle its name, was built by William the Conqueror in 1078, and was a resented symbol of oppression, inflicted upon London by the new ruling elite. The castle was used as a prison from 1100 (Ranulf Flambard) until 1952 (Kray twins), although that was not its primary purpose. A grand palace early in its history, it served as a royal residence.