For nearly 500 years, the emperors living within Beijing's opulent Forbidden City dictated who could enter and leave. Well, the gates have opened, and tourists are pouring in to see it all for themselves. Attendance is up by 2.5 million since 2010. The Forbidden City is a dream destination for some Americans, but most have never researched a trip to Everland or Lotte World. Yet these South Korean theme parks also rank among the world's 50 most-visited tourist attractions—beating out the Eiffel Tower (nearly 7 million), the Great Pyramids (4 million), and Stonehenge (1 million). And there are more surprises.