London is the capital of Great Britain and is situated on the River Thames. Important landmarks in London include the Houses of Parliament where the British government is seated, Buckingham Palace where Queen Elizabeth lives, the Tower of London which was formerly a fortress and prison but is now a museum, St. Paul's Cathedral which is the largest English church, and Westminster Abbey which is one of the oldest buildings in London where many kings and queens are buried. Trafalgar Square features a monument to Admiral Nelson, a national hero of Great Britain, and is located near the National Gallery which houses a collection of European paintings.