Olca-Paruma is a long volcanic complex. It is composed of the high conical Cerro Paruma (), the high Volcan Paruma (), west of Cerro Paruma, the high Olca (), west of Volcan Paruma, and the high Mencheca () volcanoes, which are aligned in an east-west direction. Mencheca is also known as Michincha. An additional centre is the high Cerro Olca Sur (). Directly west of Cerro Paruma lies Cerro Candelaria and north of it a saddle named Salle Orca, which leads north to another summit, Cerro Moro. Olca has a summit crater, and two craters are found on Volcan Paruma, plus at least twelve additional vents. Some vents have well-preserved craters and others are eroded. The volcanoes are accompanied by surge deposits formed during explosive activity. The basal diameter of the edifice is , the basal surface , and the volume of the edifice is .