 Calabozos is part of the South Volcanic Zone , which runs along the western edge of central Chile and extends south , jumping the border to continue its course in Argentina . This range includes at least nine caldera complexes , more than 70 of Chile 's stratovolcanoes and volcanic fields that have been active in the Quaternary , and hundreds of minor eruptive centers . The South Volcanic Zone is the most volcanically active region in Chile , and produces around one eruption per year . Its largest historical eruption was at Quizapu Crater , located 15 kilometres ( 9 mi ) to 20 kilometres ( 12 mi ) from the north side of Cerro Azul 's summit , and its most active volcanoes are Llaima and Villarrica . 
