If you've ever been intrigued by the subterranean world, plan a stay at Horse Cave KOA. It lies in the heart of one of the most significant cave regions on the planet. Beneath the area's rumpled hills, eons of dripping and flowing waters have worn through the limestone bedrock, creating a maze of underground rooms, rivers and sinkholes. Nearby Mammoth Cave National Park preserves the world's largest known cave system. Sign on for a tour for an introduction to this geological wonder. If you're up for adventure, try the belly-crawling six-hour Wild Cave Tour. Cleanup is easy at KOA, where you'll find hot showers and laundry facilities. Camping Cabins, shady Pull-Thru RV Sites, a swimming pool, mini golf and a playground for kids make this a relaxing base. In fall, the trees reward you with glorious color. Pool: Memorial Weekend - Labor Day Weekend. Max pull thru: 70 feet. Your hosts: the Gedda family.