STS503 - Arches 01 - Arches National Monument near Moab Utah has many of these natural arches. The softer surrounding stone eroded away, leaving 'clumps' sticking up from the surrounding ground. Then, as wind and scouring sand eddied around these 'clumps', it eventually wore away the center. There are many spires here also, that were too narrow to hollow out. In areas, the landscape is just as strangely beautiful and wierd as any terrain on a foreign planet that might be imagined.