The city of Rancagua is housed in the basin of the same name, which extends from the Angostura dePaine , to Angostura Pelequ�n , and is part of the Intermediate Depression . The main feature of this basin is found sandwiched between the Andes and the Cordillera de la Costa .
The Andes Mountains in this basin reaches its highest altitude, between Aconcagua and Barroso Peak, where the peaks exceed 5,500 m .
The basin has a tectonic origin and consists of fluvial-glacial sediments, volcanic. is 60 km in north-south and 30 km east-west. It has an average elevation of 400 meters
