Great Onyx Cave
An independent cave on the north bank of the Green River, open only on lantern-lit guided tours, with well-preserved stalactites, gypsum flowers and curtain formations.
Great Onyx Cave was discovered in 1915 and once operated as a privately run show cave during the Kentucky Cave Wars, before being absorbed into the national park. There are no electric lights inside. Visitors carry kerosene lanterns and follow a guide for about 2.5 hours, seeing stalagmites, flowstone curtains and gypsum crystals in the dim lamplight, which gives the tour a nostalgic atmosphere. Because the entrance lies on the north side of the Green River, you need to take a bus to get there. Tours run infrequently and spaces are limited. They are generally offered only in summer, so check schedules and book well in advance.
Opening hours
Seasonal opening
Nearby sights
- Historic Tour (Historic Entrance)
- River Styx Spring Trail
- Green River (Ferry & Canoeing)
- Grand Avenue Tour (Carmichael Entrance)
- Frozen Niagara / Domes & Dripstones
- Cedar Sink Trail
- Diamond Caverns
- Dinosaur World