Landscape Arch Trail
This natural rock opening, which measures 306 feet from base to base and looks like a delicate ribbon of rock bending over the horizon, is the longest geologic span in North America. In 1991, a slab of rock about 60 feet long, 11 feet wide, and 4 feet thick fell from the underside, leaving it even thinner. You reach it via a rolling, gravel, 1.8-mile-long trail. Easy.
