When hundreds or thousands of coral polyps build their skeletons close together, they create a calcium carbonate structure that provides habitat and food for a variety of organisms. This is known as a coral reef. Explore a virtual coral reef. More Info - Common Coral Forms; More Info - Fringing Reefs
Arch Cape is an unincorporated community in Clatsop County, Oregon, United States. It is located along the Pacific coast about 4 miles south of Cannon Beach. The Arch Cape post office, established in 1912, has ZIP code 97102. The community was named for a natural arch in the coastal rocks.
These can be enlarged by wave action, eventually forming a cave. This cave is found on the coast of California, USA. If a cave is formed in an exposed headland, it may be enlarged until it runs right through this headland. The resulting feature is called an arch. Natural arches can be seen in the photos below.