Deep in the jungles of Belize, a sacred site has begun attracting tourists that are willing to hike, swim, and climb their way to reach it. The Actun Tunichil Muknal cave, a place of great significance for ancient Maya, was discovered in 1989. After years of research by Belizean archeologist Jaime Awe and his team, the site was opened to the public in 1998. The site is home to dozens of skeletons, including the famous Crystal Maiden. Although the cave now draws much interest from adventurous tourists, it is still not widely seen: a few years ago, photography and video were banned. (Go with Nat Geo: Explore the cave on an active trip with National Geographic Expeditions)