Big Bus London Hop-On Hop-Off Tour. Discover the grandeur of London aboard the open-top, double-decker Big Bus on this hop-on, hop-off sightseeing tour. With your 1-, 2- or 3-day ticket, design a personal itinerary with dozens of possible stops, including Buckingham Palace, Hyde Park, St Paul’s Cathedral and more. Enjoy unobstructed views and fun onboard commentary as you view the city’s highlights. Hop off to enjoy included walking tours, a River Thames cruise and discounts at many local venues and shops. Book and Save 38%! Big Bus London Hop-On Hop-Off Tour.