From the latitude of Michinmahuida volcano southwards a well-defined western longitudinal valley, occupied by the Carretera Austral, divides the Andes into two chains, the eastern being the main chain, to which belong mounts Ventisquero Sur, Barros Arana and Alto Nevado, while the western chain, broken into imposing blocks, contains several high volcanic peaks such as Corcovado, Yanteles and Melimoyu.