Cahokia Mounds, Collinsville, IL - Just over the Illinois border near St. Louis are prehistoric ruins of an ancient city. Cahokia is long gone, but mounds that were once barriers and buildings of a vast empire still stand. Also, a rebuilt calendar known as Woodhenge, is every bit as puzzling and accurate as Stonehenge. The site hosts various archeological digs, and is a must see if you are cruising through Southern Illinois.
