© 2019 by Kentucky Down Under Adventure Zoo

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(270) 786-1010

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3700 L&N Turnpike Road

Horse Cave, KY  42749

I65 Exit 58

Mammoth Onyx Cave

This is one of the most beautiful and easily accessible caves in the U.S.  Mammoth Onyx Cave was discovered in 1799, and opened to public tours in 1922. Visitors will marvel at the beautiful onyx formations found in the underground chambers of Mammoth Onyx Cave. The leisurely cave tour features stalactites, stalagmites, and other formations created by water and time to naturally design an incredibly beautiful underworld scene.

Tours of Mammoth Onyx Cave are scheduled throughout the day and no prior reservations are required. Although the cave contains some steps, a small group size and leisurely pace accommodates most people. Guides welcome questions and conversation during a 30-minute tour in a comfortable and constant 60°F setting. This is an active cave: when it rains, the water drips down through the ground and into the cave continually creating new formations! There are many different formations to behold in the cave, such as stalagmites and stalactites, cave popcorn, and cave cauliflower. Unsure what cave popcorn or cave cauliflower are? Your interpreter will be happy to explain.