London is a major tourist destination with four world heritage sites, several 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 institutions such as the British Museum and the National Gallery, along with a multitude of shopping, nightlife, and entertainment venues. London's main geographical feature is the River Thames, which runs through the city from the south-west to the east.