 Calabozos is a Holocene caldera in central Chile 's Maule Region ( 7th Region ) . Part of the Chilean Andes ' volcanic segment , it is considered a member of the Southern Volcanic Zone ( SVZ ) , one of the three distinct volcanic belts of South America . This most active section of the Andes runs along central Chile 's western edge , and includes more than 70 of Chile 's stratovolcanoes and volcanic fields . Calabozos lies in an extremely remote area of poorly glaciated mountains . 
