Cahokia Mounds is a state historic site and a UNESCO World Heritage Site. The complex contains the remains of an ancient city founded by a Mississippian culture that flourished from 700-1400 A.D. and then vanished. It is the largest prehistoric city north of Mexico. Walk to the top of the 100 foot tall Monks Mound and see the film and life-size village. Don’t miss annual events that focus on Native American culture.