San Dionisio del Mar

San Dionisio del Mar sits on a peninsula that separates the Laguna Superior from the Laguna Inferior, in the east of the Isthmus of Tehuantepec, barely above sea level (13 to 20 m depending on the source). It is the seat of a 237 km² municipality in the Juchitán district, and the 2020 census counted 3,210 residents, almost the same as the 3,140 of 2010. About 86% of people identify as Indigenous and a little over half speak an Indigenous language.

This is Huave country, a language unrelated to any other. Tradition says the Huave came from what is now Nicaragua and found the Isthmus plains held by the Mixe, who withdrew to the mountains without serious fighting; later Zapotecs and Mexica pushed into those plains and drove the Huave to the coast, onto the low ground around the two lagoons. The story is much like those told in neighbouring San Mateo del Mar and San Francisco del Mar.

Fishing is the main livelihood. People also grow maize, sesame, sorghum, squash and fruit, and keep cattle, horses and pigs. The climate is warm and sub-humid with summer rains; the scrub holds mesquite and guanacaste, and wildlife includes iguana, armadillo, opossum and pigeon.

Cascalote beach is about 17 km away, roughly 20 minutes by car, and nearby localities include Chicapa de Castro, about 15 km away in a straight line, and Huamúchil, about 11 km.