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.
Aloba Arch is one of the most magnificent natural arches in the world, located in the Ennedi Range of the Sahara Desert in Chad. This is not a natural bridge, but a very large alcove arch. Aloba Arch has a span of approximately 250 feet, but perhaps more striking than the span, is the sheer height of the arch.