This major global city is the host of the most extensive subway network in the world, and has the world's busiest airport. London is the capital of England and the United Kingdom. It has many well known touristic places to visit, such as the Tower of London, the House of Parliament, the Tower Bridge, the Buckingham Palace, the British Museum, the National Gallery, the St. Paul's Cathedral, and for those who enjoy sports, the Wembley Stadium.