A coral reef is made of thin layers of calcium carbonate A coral reef is made of thin layers of calcium carbonate National Ocean Service National Oceanic and Atmospheric Administration U.S. Department of Commerce
Arches is located in northeastern Utah, near the city of Moab. The park is famous for over 2,000 natural stone arches and offers much to the outdoor traveler. There is a 40-mile paved loop tour of the park with numerous trailheads and outlooks.
Arches are fascinating in that they are a truly natural form of bridge. It is the shape of the structure that gives it its strength. An arch bridge doesn't need additional supports or cables. In fact, an arch made of stone doesn't even need mortar. Ancient Romans built arch bridges (and aqueducts) that are still standing, and structurally sound, today.