Covering an area of 1,500 hectares, it's located northwest of Catemaco Lagoon and is characterized by a mountainous region with numerous volcanic cones, with the San Martín Volcano being one of the most important, boasting an impressive 1.5 km diameter crater. 

In the region, 276 bird species, 97 reptile species, 37 amphibian species, and 100 mammal species have been identified. 

Due to the high precipitation in the area, there are several rivers and waterfalls that are an attraction, along with the incredible variety of orchids.