Mammoth Cave National Park

Mammoth Cave sits in south central Kentucky, about an hour and a half from Louisville and Nashville. It is the longest cave system on earth, with more than 400 miles of mapped passageways and new tunnels still being found. Take a ranger led tour past the Giant's Coffin and the Bottomless Pit, or crawl the Wild Cave Tour by headlamp through undeveloped passages. The cave stays 54 degrees year round, but spring and fall are the time to go, when the surface trails are at their best and tours are easier to book.

Discovery Pick, HannahOutThere

Why this one matters

This is the longest cave system on earth, an underground world that keeps unfolding long after you think it should end. The four mile Grand Avenue Tour walks you through room after room of it. And if you want it raw, the Wild Cave Tour has you crawling by headlamp through undeveloped passages, the way the first explorers saw them.

Mammoth Cave National Park

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