The Emerald Mound Site is a Plaquemine Mississippian period archaeological site located on the Natchez Trace Parkway near Stanton, Mississippi, United States. The site dates from the period between 1200 and 1730 CE. The platform mound is the second-largest Pre-Columbian earthwork in the country, after Monk's Mound at Cahokia, Illinois. The mound covers eight acres, measuring 770 by 435 feet at the base and 35 feet in height. Emerald Mound has a flat top with two smaller secondary mounds at each end. Travelers in the early 19th century noted a number of adjoining mounds and an encircling ditch that are no longer present. Emerald Mound was stabilized by the National Park Service in 1955. It was declared a National Historic Landmark in 1989.