If you have the chance, it's really worth making the trip to Cahokia, IL. It was the capital of one of those civilizations that peaked in the 12th century, and

If you have the chance, it's really worth making the trip to Cahokia, IL. It was the capital of one of those civilizations that peaked in the 12th century, and you can still climb the monumental earthworks and gain a sense of the place. Any society that DIYs a mountain in Illinois deserves to be remembered.