Zhangjiajie Glass Bridge

Zhangjiajie National Forest Park is full of natural wonders that draw thousands of visitors a day, from misty forests to towering sandstone pillars. Allegedly, its landscape even inspired the scenery of James Cameron's Avatar. But it's not rock formations or trees that tourists have been flocking for lately–it's a bridge. A 1,400-foot-long, 900-foot-high bridge made out of glass.

This bridge, opened in the summer of 2016, comes as part of a trend in glass suspension structures. There's "Brave Men's Bridge", located in the same natural preserve as the Zhangjiajie bridge, as well as a swath of other Chinese glass bridges in both urban and natural settings. All of these have been constructed within a decade of each other, each trumping the last in superlatives. The Zhangjiajie glass bridge currently holds the record as both the longest and the highest in the world. The appeal of these attractions is both the ability to see the natural landscape below one's feet and the element of fear inherent in walking on such a massive structure made of delicate material.

As if that wasn't enough to terrify, one of China's other glass walkways cracked under the feet of visitors just two weeks after its opening. Though authorities assured the public the crack in the glass was merely superficial and no one was in any danger, it's understandable why people were scared. When the Zhangjiajie bridge was unveiled, a number of publicity events were staged to prove the bridge's sturdiness, including driving a car across it and whacking the inches-thick glass panes with sledgehammers. The bridge stood the test, but to ensure safety only 600-800 people are allowed to partake in its glass wonder at any given time.