Cruise ships are the ultimate and most comfortable way to sail the seas and, while most cruise ships are pretty luxurious, none can match the incredible size and on-board facilities of the Royal Caribbean MS Allure of the Seas. The Allure is officially the largest passenger ship on the planet and measures an impressive 362m (1,187ft) in length, weighs an eye-watering 100,000 tons and contains an incredible 16 passenger decks! If the thought of being stuck onboard a ship sounds a little boring though, the Allure might make you think again. The ship contains facilities that would make a large town jealous, including five separate swimming pools, a surfing pool, a basketball court, crazy golf, rock climbing, a zip line, an ice rink, a central park (with real trees!), a funfair, a spa, shops, restaurants, bars, a theatre, an outdoor cinema and a casino. If global warming does eventually turn the earth into a giant swimming pool, we bagsy a room on the Allure!