World’s largest known underwater cave system next to Systema Ox Bel Ha, total explored length – 346.7 km.
| Location, GPS coordinates: | 20.3177 N 87.4096 W |
| Categories: | Caves, Geographical extremes |
| Values: | Geology |
| Rating: |  (5 / 5) |
| Where is located? | North America, Mexico, Quintana Roo, som 13 km north-east from Tulum |
