Mammoth Cave National Park
Mammoth Cave, KY
Mammoth Cave is the world's longest known cave system with over 426 surveyed miles of passages. The cave was developed as a tourist site beginning in the 1810s and is internationally significant for the work of enslaved African American guide Stephen Bishop, who mapped much of the system in the 1840s and 1850s. The park is a UNESCO World Heritage Site and an International Biosphere Reserve.