Seneca Caverns
Show Cave · Bellevue, Ohio
An earthquake crevice rather than a solution cave, found in 1872 when a dog fell into it, and descended in seven rough levels to an underground river that is part of the Bellevue karst. It is deliberately undeveloped — no paved walkways, no railings in most of it — and the operators call it the caviest cave in the country, which is a fair description of the experience.
15248 East Thompson Township Road 178, Bellevue, Ohio, 44811, United States
SEASONAL — open roughly late spring to early autumn, with limited weekend operation at the edges of the season and CLOSED FOR WINTER. Guided tours only, on a rolling schedule.