Lake Atitlán is a lake in the Guatemalan Highlands of the Sierra Madre de Chiapas, in the Sololá Department of northern Guatemala. "At the water" is the meaning of "Atitlan". It is a fusion of simple Nahuatl words that belies the complexity of the entity it identifies.

The lake basin is volcanic in origin, filling an enormous caldera formed in an eruption 84,000 years ago. It is technically an endorheic lake (lacking direct flow to an ocean) but substantial seepage feeds two nearby rivers. Atitlan is recognized to be the deepest lake in Central America, with maximum depth about 340 metres. It is approximately 12 x 5 km, with around 20 cubic km of water. The lake is shaped by deep escarpments which surround it and by three volcanoes on its southern flank. Lake Atitlan is further characterized by towns and villages of the Maya people.

Volcán San Pedro (or Las Yeguas) (3,020 metres) is a stratovolcano on the shores of Lago de Atitlán. At its base is the village of San Pedro La Laguna.