Longest cave system
The current longest cave system record is 426 miles, held by Mammoth Cave System, set on September 11, 2021. Last checked October 10, 2026.
426
miles
Mammoth Cave System
- Holder
- Mammoth Cave System
- Record
- 426 miles
- Metric
- 686 km
- Exact figure
- More than 426 miles (about 686 km) of surveyed passageways
- Location
- Kentucky, United States
- Date set
- September 11, 2021
- Recognized by
- Cave Research Foundation
- Last checked
- October 10, 2026
Sources
- nps.gov Mammoth cave national park adds new miles to cave length
- livescience.com Mammoth cave system kentucky record
- nps.gov Read the source
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