The Cuatrociénegas biosphere is the only home of the endangered Coahuila Box Turtle, whose mating grounds have dried up.

Las Playitas, one of the lagoons in the reserve, is one of the most popular spots in the reserve for visitors, but the tourism boom has contributed to overextraction and alleged land theft.

Dairy companies started to appear in the area around Cuatrociénegas in the early 2000s, pumping out massive amounts of water from under the ground to feed their fields of water-hungry cattle feed.

Tanque Nuevo is a community of 73 farmers just south of the nature reserve, which suffers from frequent water shortages. Temperatures in the area can reach a baking 47 degrees Celsius.

The farmers of Tanque Nuevo have been locked in a 16-year legal battle with dairy firm Beta Santa Mónica, which they say has used fraud and corruption to illegally occupy their land and steal their water.

Dusk falls in the city of Cuatro Ciénegas de Carranza, named after the revolutionary leader Venustiano Carranza who was born there.

Temperatures in the Cuatrociénegas valley can reach 47 degrees Celsius, and the area sees little rainfall. Today some 70 percent of Mexico is considered at risk of becoming desert.