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Hike Or Go Spelunking At Oklahoma's Underrated State Park With The World's Largest Natural Gypsum Cave
Sometimes the best adventures are in the places we least expect, and that's certainly the case with this marvelous gypsum ...
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One Of The World's Longest Caves Is A Hidden South Dakota Crystal-Filled Monument That Literally Dazzles
West of the town of Custer lies a literal gem of a destination: Jewel Cave National Monument. Named for the shimmering calcite crystals that adorn its chambers, this underground marvel stretches ...