One of the 10 largest natural arches in the world, Landscape Arch is located in the Devils Garden section of Arches National Park in Utah, the US. Landscape. The Landscape Arch is considerably old and almost near the end of its lifecycle. In its thinnest section the arch is only 6 feet thick, yet it supports a span of rock 290 feet long. The arch could collapse at any time. Photo credit: Julayne Farmer.