The Devil's Bridge, towering at 50 feet with ... as awe-inspiring as the rock formations in Arches National Park. Ascending 400 feet, the 1.8-mile round-trip hiking trail gives hikers access ...

The catch? At its thinnest point, the arch is just 11 feet thick. (Consider it nature’s equivalent of a Jenga tower.) Scientists believe it’s not a question of if it will collapse, but when.