Constructed of every type of sea shell and animal bone imaginable, and native to the area, no one really knows exactly why they were built. The most plausible theory is that the ancients, for lack of a better idea, simply piled their garbage around their homes and camps; thus creating a circular trash heap, around a common area; thus recycling their refuse into a fence and boundary marker that could have also served as protection from wild animals, strong winds and other tribes. Today the remains of only twenty shell rings still exist; protected by law and listed on the National Register of Historic Places; there is evidence to support the theory that some may be as old as 10,000 years.
There were originally believed to have been four of these mysterious rings on Hilton Head; however two of them were destroyed years ago, when material was harvested from them to make “tabby”. Perhaps some of the remnants of these two rings are still visible in the Stoney-Baynard ruins in Sea Pines Plantation; this is actually plausible, as one of the two remaining shell rings is located near the east entrance to the Sea Pines Forest Preserve. The Sea Pines ring, believed to date approximately 4,000 years, is about one hundred-fifty feet in diameter. The other remaining Hilton Head ring can be viewed at the “Green Shell Enclosure”, on the north end of the island, off Squire Pope Road.