Hanging by a Thread
Mile 1,528, Arches National Park, UT
Landscape Arch is the longest (306 feet), most popular—and most fragile—arch among the 2,000 or so said to have been catalogued within Arches National Park. Its thin bridge became more delicate after a large slab of it fell following a nearby lightning strike in 1991. Because of its tenuous future, a trail that runs underneath the arch is now closed.