Carter Caves State Resort Park in Eastern KentuckyYou'll find one of the more popular cave systems in Kentucky not named Mammoth Cave at Carter Caves State Resort Park, about 90 minutes east of Lexington. The Bat CaveThe longest cave at Carter Caves State Resort Park, the Bat Cave is devoid of electricity and handrails and is 100% undeveloped. An estimated 28,000 bats are being protected in Carter Caves' Bat Cave, but I'm not sure tourists can interact with them. If you have an opening, Carter Caves State Resort Park is calling. RANKED: Here are the most popular national parks To determine the most popular national parks in the United States, Stacker compiled data from the National Park Service on the number of recreational visits each site had in 2020.