London is a fascinating city laden with history, filled with museums and art galleries, beautiful green parks, fantastic shopping and dining, a vibrant theatre scene, and, of course, royalty. London is truly a city that has it all. The changing of the guard at Buckingham Palace is a not-to-be-missed experience, as is watching the minutes tick away at Big Ben, probably the world's most famous clock. Another London must is riding a double-decker bus across Tower Bridge over the Thames River.