# Sistema Sac Actun

- **Country:** Mexico
- **Coordinates:** 20.246556, -87.464111
- **Mark:** Gfi-set01-cave_blue.svg
- **Depth:** 119.2 m
- **Length:** Underwater: 378.56 km
- **Geology:** Limestone
- **Location:** Tulum Municipality, Quintana Roo, Mexico
- **Discovery:** November 26, 1987
- **Difficulty:** Advanced cave diving
- **Photo Caption:** Sac Actun
- **Entrance Count:** 228 Cenotes
- **Label Position:** left

Sistema Sac Actun (, ) 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. , it is the second longest underwater cave system in the world, only surpassed by Sistema Ox Bel Ha.

**Source:** https://en.wikipedia.org/wiki/Sistema_Sac_Actun (Wikipedia, CC BY-SA)