London is a major tourist destination with four world heritage sites, a number of royal parks, and numerous iconic landmarks such as the Houses of Parliament, Tower Bridge, the Tower of London, Westminster Abbey, Buckingham Palace and the London Eye. Other attractions include famous institutions such as the British Museum and the National Gallery, along with a multitude of shopping, nightlife and entertainment venues in the West End. London's main geographical feature is the River Thames which runs through the city from the south-west to the east.
The Clock Tower is the world's largest four-faced, chiming turret clock. The structure is situated at the north-eastern end of the Houses of Parliament building in Westminster, London. It is often mistakenly called "Big Ben"