Mammoth Cave is the longest known cave system on earth — over 426 mapped miles of passages, with new survey adding miles every year. The cave was a tourist attraction before Kentucky was a state, and tours have run continuously since 1816 — the longest unbroken stretch of cave tourism in the world. The park became a UNESCO World Heritage Site in 1981 and an International Biosphere Reserve in 1990. Above ground, 53,000 acres of Cumberland Plateau forest sit on top of the cave system, with the Green and Nolin Rivers cutting deep, scenic gorges. From I-65 the access is Exit 48 in Cave City, then 10 mi west on KY-70 and Mammoth Cave Parkway to the visitor center. Park entry is free, but every cave tour requires a paid reservation and they routinely sell out 1-4 weeks in advance during summer.
- Longest known cave system on earth — 426+ mapped miles (more than the next two combined)
- Continuous commercial tours since 1816 — longest unbroken cave-tourism history in the world
- Designated a UNESCO World Heritage Site (1981) and International Biosphere Reserve (1990)
- Above-ground area: 53,000 acres of Cumberland Plateau forest with 70+ above-ground miles of trail
- Park entry is free; cave tours require separate paid reservations