8. Caribbean Bay -- Gyeonggi-do, South Korea
Scariest slide: Despite a name that sounds all innocent-like, the 85ft-tall Water Bobsleigh is pure evil. Also, there's three of them.
Why it's worth the visit: Not only are there six distinct areas offering something for every water enthusiast, but there's also the world's longest lazy river, The Wild River (which, interestingly enough, is not said lazy river but a ride where water surges push you up a 62ft hill), and even a spa, salt sauna, and nap room.