From the Geocache Description
Southeastern North Carolina is home to a unique geological formation and it is the only natural rocky shoreline in NC. The coast near Fort Fisher, is host to a hard rock outcropping of coquina rock that is rare and distinctive.
Coquina is a sedimentary rock that is cemented together by seashells or coral, giving it a rough, gravelly look and feel. Because shells are made of calcium carbonate, coquina is formally a limestone. Coquina is the Spanish word for cockleshells or shellfish. Coquina forms near shore, where wave action is vigorous and sorts the sediments well. Notice that the pieces are all broken and rounded by the abrasion of the waves. Experts disagree on just how long ago the rock was created, but it’s a relatively young formation, with estimates of its origin ranging from 12,000 to 80,000 years ago. The rock was used in years past as a building material for homes and even forts, because it was good at absorbing cannon fire.
This group of Sanderlings provided many photo opportunities while I watched.