Who Built the Stone Wall on top of Fort Mountain in Murray County?

I have long been interested in the early native tribes of Georgia. As a matter of fact, I am reading Dr. Max White's The Archaeology and History of the Native Georgia Tribes now in an effort to learn more about the Paleoindians, Archaic Period inhabitants, Woodland Indians, Mississippians, and the recent tribes in Georgia (Creek and Cherokee).  One of the greatest mysteries from the past in Georgia that relates to native tribes, or possibly does, is the story of the stone wall atop Fort Mountain in Murray County.
On the mountain, there is what looks like a stone wall made with rocks and other stones. It was once thought that the wall was built for defense by some tribe that occupied the mountain. However, there is no water source to be found inside the wall, and this would make those being defended by the wall more vulnerable than if the wall were not there.  So this has been ruled out.
What is most interesting about this story is the Cherokee legend that is told in an attempt to answer who and why.  Apparently, the Cherokees talk about a race of people with "moon-shaped eyes" who arrived in their homeland and constructed the wall.  They were said to live underground, be nocturnal, and wear beards.  Who were these people.  Some have answered that question with another legend, this one of Prince Madoc of Wales.  This legend focuses on a Welsh prince who sailed from Europe in the 12th century, some two hundred plus years before Columbus.  He never returned to his homeland, but native legend tells of a race of fair-skinned men who landed near Mobile Bay and traveled inland, all the while making contact with native peoples, and, in some places, building forts, including the one on Fort Mountain.
There are quite a few legends about Fort Mountain. Some say that Hernando De Soto built the wall while in the area as protection from the Creeks. Others say that a tribe of natives used it as an observatory.  There is a Georgia Historical Marker there that discusses the mystery behind the wall.  Check it out at:
http://www.hmdb.org/marker.asp?marker=11590

There is also a great site about ancient civilizations in Georgia, and it can be found at:
http://lostworlds.org

                                                           (photo courtesy of lostworlds.org)
This is one of the most interesting mysteries of early Georgia.