The Old Stone Fort is a prehistoric Native American structure located in Coffee County, Tennessee, in the Southeastern United States. The structure was most likely built between 80 and 550 AD during the Middle Woodland period. It is the most complex hilltop enclosure found in the South and was likely used for ceremonial purposes rather than defense.
The structure is now part of Old Stone Fort State Archaeological Park, one of two archaeological parks in Tennessee (the other being at Pinson Mounds near Jackson). The site is listed on the National Register of Historic Places.(Wikipedia)