# Sistema Huautla

- **Country:** Mexico
- **Coordinates:** 18.121214, -96.800008
- **Depth:** 1560 m deep.
- **Length:** 100,242 m total length.}}
- **Location:** Sierra Mazateca, Oaxaca, Mexico

In an expedition in 1977, the deepest point of the cave system was discovered after staging multiple underground camps, a flooded tunnel at 1325 meters, known as the San Agustín sump. Subsequent scuba diving expeditions in 1979 and 1981 proved logistically insufficient to transport equipment to explore it further. In 1994, during a 135-day expedition of 44 people, mostly from the UK and the US, 11 were cave diving using closed cycle life support systems called rebreathers. They explored three parts of the sump system and discovered an upstream tunnel leading to the only known exit for the water that enters the Huautla caves, the spring of Peña Colorada. During a two-month expedition in 2013 involving 40 team members from the UK, USA, Canada, Poland and Mexico, cavers entered through Sótano de San Agustin; it took divers three weeks to reach "what looked like a calm, rock-enclosed lake about 100 feet wide", the San Agustín sump.

![Photo of Sistema Huautla](https://upload.wikimedia.org/wikipedia/commons/f/ff/Sistema_Huautla_4.jpg)

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