1. Cenote Dos Ojos — Tulum, Mexico
Dos Ojos is a flooded cave system located south of Playa Del Carmen and north of Tulum, on the Caribbean coast, in the state of Quintana Roo, Mexico. The exploration of Dos Ojos began in 1986 and has never stopped since. The documented underwater extend of the cave system is at least 61 km.
Dos Ojos has remains in the top 10 longest underwater cave systems in the world. Dos Ojos contains the deepest known cave passage in Quintana Roo with 118 meters / 396 feet of depth located at The Cenote Pit.