Laguna de Totolcingo, Saline lake in Oriental Basin, Mexico.

Laguna de Totolcingo is a saline lake in the Oriental Basin whose water level changes significantly with the seasons. The lake expands during the rainy season from June to October and shrinks considerably during the dry months from November to May.

The lake lies at the lowest point of the Oriental Basin, a semi-arid endorheic basin at the eastern edge of the Mexican high plateau. It also takes the name Tequesquital from the tequesquite, a natural mineral salt it contains. Most of the small streams born in the surrounding hills, notably a spring in the Sierra de Mazatepec near El Carmen, vanish before reaching the lake bed.

The lake's alternative name, Tequesquital, comes from the tequesquite that forms in its waters. This mineral salt, harvested from the flats, has long seasoned Mexican cooking, and the name ties the lake directly to that use.

Access is via Federal Highway 136 to Las Derrumbadas, on the Puebla side bordering Tlaxcala; buses from nearby towns also serve the area. Go during the rainy season, June to October, when the basin actually holds water; from November to May it evaporates almost completely. Local authorities protect the site, so do not leave waste or disturb the birds.

The lake's other name, Tequesquital, comes from the tequesquite it contains, a natural mineral salt that local people gather and use as a traditional seasoning in Mexican cooking. The same salinity that limits flora and fauna to a few grasses and migratory birds has long made the lake a source of this salt.