Meramec Caverns, the oldest attraction on Route 66, offers guided tours of the rarest and largest cave formations in the world. Located in the foothills of the Ozark Mountains southwest of St. Louis, the cave sheltered Native American tribes and later provided minerals to French colonial miners. Civil War garrisons used the cave’s deposits to manufacture gunpowder. Outlaw Jesse James hid both men and horses in the dark passages in the 1870s. Legend also says the cave was a stop on the Underground Railroad for escaping slaves. Don’t miss the Stage Curtain, the largest single cave formation in the world, and the Underground River.
Adventure seekers can also explore nearby Onondaga, Cathedral and Fisher caves or canoe along the scenic Meramec River and the crisp Huzzah and Courtois creeks.