Olentangy Indian Caverns

The Olentangy Caverns are a series of caves, natural passages and rooms in Delaware, Ohio, occupying three different levels. The caverns were formed millions of years ago by an underground river that cut through the limestone rock. They were used by the Wyandotte Indians as a refuge from the weather and from their enemies the Delaware Indians. Artifacts found in the caverns indicate that it was used by the Wyandotte as late as 1810. The Olentangy Caverns are located at 1779 Home Road, and are open seasonally for self-guided tours.

Cave data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).