Since time immemorial, Mother Nature has been hard at work in Arches National Park, famous for its namesake rock formations that splash soaring arcs of red-orange sandstone against the bright blue sky of Utah. True to its name, Arches has the highest concentration of natural stone arches of anywhere on Earth, from the graceful 306ft-long Landscape Arch to tucked-away Delicate Arch, a Utah icon so photo-worthy that it’s emblazoned on the state’s license plates.