 Quetrupillán lies on the border between the Los Rios Region and the La Araucanía Region, in the Southern Volcanic Zone.Together with Villarrica and Lanín it forms a northwest-southeast alignment of volcanoes, which may be a transcurrent fault.The Cordillera El Mocho and Quinquilil volcanoes are likewise situated on this alignment, both are deeply eroded composite volcanoes of small dimensions.