At least 4000 feet in the air a three-foot-wide walkway clings to one face of Tianmen Mountain in Zhangjiajie, China, above a rocky ravine. With a glass bottom, the tourist attraction provides a crystal-clear view of where one wrong step could take you.
The Blue Cave is one of Montenegro's top attractions. It's a small cave that you can only get to by boat and it's famous for its iridescent blue that makes the whole cave glow. Find out about the cave and where to find a tour here.