Grand Caverns has operated continuously since 1806, making it the oldest show cave in the country still giving tours — a National Natural Landmark, with Civil War soldiers’ signatures still visible in the rock. The standard walking tour runs about 70 minutes.

Park entry and parking are free, but the cave tour itself is not — budget for a real ticket cost rather than assuming this is a free stop; check current pricing through their online booking system or call ahead. Reservations are strongly recommended. The cave is open year-round with seasonal hours.