Cahokia was a vast pre-Columbian metropolis

Cahokia is one of the largest indigenous cities in North America, located in southwestern Illinois. It housed up to 30,000 inhabitants in the 12th century and spanned 1,600 hectares containing 120 mounds and temples. This major archaeological site, including notably Monks Mound, attracts 250,000 visitors per year today since its classification as a World Heritage site in 1982.