Grand Canyon Glass Bridge

The Zhangjiajie Grand Canyon Glass Bridge is exactly as unreasonable as it sounds: 430 meters of transparent glass, 300 meters above a river canyon, wide enough for a crowd and thin enough to make your legs negotiate. It is the longest of its kind on earth.

The canyon below has its own walkway, waterfalls, and a boat ride out. Cross once with your eyes open, once with your phone held high, and once holding onto a stranger - all three are the experience.