London is the capital city of the United Kingdom. It is located on the River Thames in southeast England. Some key facts about London are that it has a population of over 8 million people, making it one of the most populated cities in Europe. London is also known for its diversity, with people from all over the world living in the city. Major landmarks include Big Ben, Buckingham Palace, Westminster Abbey, Tower Bridge, and St. Paul's Cathedral. The city has extensive public transportation options and holds many annual ceremonies and traditions, such as the Changing of the Guard and Trooping the Colour.