See londons highlights by retro double decker bus and cruise boat on this 55 hour tour which includes a guided tour of westminster abbey take a seat on a vintage red routemaster bus and pass top london sights including trafalgar square big ben and the houses of parliament then soak in more london landmarks such as tower bridge and the tower of london on a thames river sightseeing cruise finally crown your day with a visit to stunning westminster abbey a unesco world heritage site th