Cerro Machín is a stratovolcano located in Tolima Department, Colombia. Cerro Machin is a volcanic plug that is approximately the same age (1,000,000+ years) as the Ruiz-Tolima Massif and has the appearance of being part of that volcanic system. Its sisters are Nevado del Tolima, ; Santa Isabel, , Nevado del Ruiz, , plus nine other lesser volcanoes and a volcanic South Wall containing in excess of thirty volcanic domes.