| Sistema Sac Actun | |
|---|---|
  Sistema Sac Actun Location in Mexico | |
| Location | Tulum Municipality, Quintana Roo, Mexico |
| Coordinates | 20°14′47.6″N 87°27′50.8″W / 20.246556°N 87.464111°W |
| Depth | 119.2 meters (391 ft)[1] |
| Length | Underwater: 378.56 km (235.23 mi)[1] Total: 386.122 km (239.925 mi)[2] |
| Discovery | November 26, 1987 |
| Geology | Limestone |
| Entrances | 228 Cenotes[1] |
| Difficulty | Advanced cave diving |
Sistema Sac Actun (Yucatec Maya: sak aktun, lit. 'white cave', Spanish: sistema, lit. 'system') is an underwater cave system situated along the Caribbean coast of the Yucatán Peninsula with passages to the north and west of the city of Tulum. Discovery of a connection to Sistema Dos Ojos in 2018 made it the longest known underwater cave system. As of January 2023[update], it is the second longest underwater cave system in the world, only surpassed by Sistema Ox Bel Ha.
The remains of a mastodon and a human female that might be the oldest evidence of human habitation in the Americas have been found in the cave.
- ^ a b c "List of Long Underwater Caves in Quintana Roo Mexico". Quintana Roo Speleological Survey. National Speleological Society (NSS). January 10, 2023. Retrieved 10 January 2023.
- ^ "Dry Caves and Sumps of Quintana Roo Mexico". Quintana Roo Speleological Survey. National Speleological Society. January 10, 2023. Retrieved 10 January 2023.