Cahokia Mounds

Cahokia Mounds, just east of St. Louis, was the largest pre-Columbian city north of Mexico, home to an estimated 10,000 to 20,000 people at its peak between roughly 1050 and 1150 CE during the Mississippian period. Its builders raised more than 120 earthen mounds, including the massive Monks Mound, and the site was designated a UNESCO World Heritage Site in 1982 for its scale and sophistication. The city's decline by around 1400 remains one of North American archaeology's enduring mysteries, and its mounds include the site of a documented large-scale ceremonial burial. Visitors today describe shadowy figures moving between the mounds at dusk and faint whispers carried on the wind.