Designated a National Historic Landmark, The Emerald Mound Site, located around 10 miles northeast of Natchez, is the second largest Mississippian Period ceremonial mound in the United States, surpassed only by Monk’s Mound near Cahokia, Illinois.
Built and used between the years 1200 C.E. (current era) and 1730 C.E., the 35-foot-high mound covers eight acres and measures 770 feet by 435 feet at its base. Two secondary mounds sit atop the primary mound, bringing the total height to approximately 60 feet. The larger one at the west end measures 190 feet by 160 feet by 30 feet high. Early records suggest there were six, smaller mounds located along the sides of the primary mound, but visual evidence of these smaller mounds has long since disappeared.
The mound was built by depositing earth along the sides of a natural hill, thus reshaping it and creating an enormous artificial plateau.
Emerald Mound was a ceremonial center for the local population, which resided in outlying villages and hamlets. Its builders were ancestors of the Natchez Indians. By the late 1600s, the Natchez had abandoned Emerald and established their capital at the Grand Village some 12 miles to the southwest.
Further information about the Mound is available on the National Parks Service information page here.