Double O ArchDouble O Arch is a large natural arch located in Arches National Park near Moab, Utah, in the United States. It is the second-largest arch within the Devils Garden area, after Landscape Arch.BackgroundThe formation comprises two large arches stacked on top of each other in the same fin of rock. The larger "O" stretches across while the smaller arch below measures approximately across. The arch can be reached via a strenuous round trip hike on the Devils Garden Trail.