It is located south of the state of Chiapas, on the Pacific Coastal Plain. Includes part of the town of Pijijiapan, Mapastepec Acapetahua, Huixtla, Villa Comaltitlán and Mazatán. Their access is possible via highway 200, on the stretch between Mapastepec and Huixtla.
It is a wetland of international importance for biodiversity protection..