The Great Serpent Mound
An astounding 1,348-feet long, this meaning and purpose of this effigy mound is still in question. Some say it is depicting a serpent swallowing an egg and others say the curving tendril is supposed to represent the phases of the moon. Whatever meaning it is to convey, the mound was most likely built around 300 BCE. This ancient site is open year round from 9 AM to dusk.