More than 420 miles of passages have been surveyed, far longer than any other known cave. Location: Mammoth Cave National Park, Kentucky. Key figure: 420+ miles. Part of the One State One Record (USA) campaign. Reference record compiled from public sources; not certified by The Book of World Records. Source: https://www.livescience.com/mammoth-cave-system-kentucky-record
Record no. MRB-2026-007187
Longest Known Cave System in the World
Reference Record – Not Certified
This record is compiled from publicly available sources for reference. It has not been examined or certified by The Book of World Records.