Around 2,000 years ago, Native Americans built a rock and earthen wall around a 50-acre hilltop plateau between the Duck and Little Duck Rivers. Archaeological investigations here in 1966 recovered artifactual and radiocarbon data indicating that this hilltop enclosure was constructed during the Middle Woodland period, from AD 80 to AD 550. In the 1990s, archaeologists determined that the entrance to the enclosure is aligned with the summer solstice sunrise on June 21, suggesting that rituals and ceremonies took place on a seasonal basis. Recent archaeological studies provide a more accurate account of this ceremonial center, which is now open as a Tennessee State Park and is listed in the National Register of Historic Places.