Just outside of St. Louis, on the other side of the state border, is Cahokia Mounds State Historic Park. The Cahokia Mounds are a fascinating landmark formed by American Indians who lived there more than 800 years ago. The mounds are believed to signify the largest pre-Columbian city north of Mexico. There are 69 remaining mounds which are now covered in grass. The largest of these mounds is Monks Mound, and it is more than 100 feet tall. Another interesting part of Cahokia is Woodhenge, a large circle formed by 48 wooden posts that aligns with the solar calendar, which makes it very similar to Stonehenge in England.
Show on map