Cerro Overo is an isolated basaltic maar in northern Chile, located on the lower NE flank of Chiliques volcano, west of the Salar de Aguas Calientes, and 20 km north of Lascar volcano. The fresh morphology suggests a possible Holocene age. It contains a 600-m-wide and 80-m-deep crater.
Cerro Overo erupted the least silica-rich volcanic rocks (basalts) found in this part of the Central Andes.