Near Fort Mountain State Park in North Georgia, there are remains of stone walls, long and built low. Legend has it a white race built them hundreds of years ago. They eventually disappeared, one theory is that they were killed off by Indians. The web site identifies the walls as built by Indians, but the signs in the park identify the builders as white-skinned and fair-haired.
http://gastateparks.org/info.asp?id=42&linkval=fortmt&siteid=5
Another one in Alabama called Fort Mtn also, I think, and at least one in Tn. Evidence also nr Lookout Mtn, Tn/Ga.