With over 200 miles of mapped passageways (and a mind-boggling amount yet to be discovered), Jewel Cave National Monument is the third longest cave in the world. And all of that lies in just four square miles beneath South Dakota. The folks who named the cave did so appropriately (and not after the singer), because inside lies a dark, ominous cavern lined with shimmering crystals. This episode, we recount our visit and about sharing our RV with our first on-the-road guest, plus, we'll talk with our first honest-to-goodness park ranger, Michael Wiles, Jewel Cave's Chief of Resource Management.

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