Onyx Cave
Onyx Cave denotes several caves in the United States:
- Onyx Cave (Arizona) , National Natural Landmark
- Onyx Cave (Arkansas) , the oldest visitable cave in Arkansas
- Onyx Cave, Missouri , listed on the NRHP
-
Great Onyx Cave , in Mammoth Cave National Park, Kentucky
- Great Onyx Cave Entrance , listed on the NRHP
- Crystal Onyx Cave , Kentucky