Geography of Santiago:

The city lies in the centre of the Santiago Basin, a large bowl-shaped valley consisting of a broad and fertile plain surrounded by mountains. It is flanked by the main chain of the Andes on the east and the Chilean Coastal Range on the west. On the north, it is bound by the Cordón de Chacabuco, a transverse mountain range of the Andes, whereas at the southern border lies Angostura de Paine, where an elongated spur of the Andes almost reaches the Coastal Range. Santiago Basin is part of the Intermediate Depression and is remarkably flat, interrupted only by a few hills. Among those are Cerro Renca, Cerro Blanco and Cerro Santa Lucía.
The Andes mountains around Santiago are quite tall, culminating in Tupungato volcano at 6,570 m (21,555 ft). Other volcanoes include Tupungatito, San José and Maipo. Cerro El Plomo is the highest mountain visible from Santiago's urban area.
Santiago is situated mainly on a plain known as the Santiago basin. This basin is part of the Intermediate Depression and is clearly delimited by the string of Chacabuco in the north, the Andes Mountains in the east, the narrowness of Paine in the south and the Cordillera de la Costa. It is approximately 80 km in a north-south direction and 35 km from east to west.
For hundreds of millions of years, the current territory of the city was covered by the ocean and marine sediment, the only land mass near the existing Coastal Cordillera. The morphology of the region begin to take its present form since the late Paleozoic, when it begins the subduction of the Nazca Plate under the South American plate, then belonging to the continent of Gondwana. This subduction generated foldings of the crust from the Triassic, lifting the rocks that give rise to the Andes. Subsequently, new activities generate tectonic subsidence of the great rock mass forming the depression lifted.
At present, Santiago lies mainly in the plain of the basin, with an altitude between 400 in the western areas and reaching the 540 on the Plaza Baquedano, presented some hills in the area of Cerrillos. The metropolitan area has surrounded some of these islands, mountains, as in the case of Cerro Santa Lucia, Cerro Blanco, the Renca Calán and that 800 meters is the highest point of the city. Southwest of the city there is a string of rocky hills several islands within the highlighting Cerro Chena. To the west are also presented some of the main stage of the Cordillera de la Costa, the Oak Hill High with 2185 meters of altitude, and the Maipo River area alone in the mountain range loses height. During recent decades, urban growth has expanded the boundaries of the city to the east closer to the Andean Precordillera. Even in areas such as La Dehesa, Lo Curro and El Arrayan has been reached to overcome the barrier of 1000 meters of altitude. Some low-lying foothills of the Andes emerge and goes into the basin, as is the If the mountain range of The Pyramid and the hill Cerro San Cristobal, in the northeastern sector of Santiago.
To the east, stands the massive call Ramon Sierra, a mountain chain formed in the foothills of the Precordillera due to the action of the fault Ramon, reaching 3296 meters at the Cerro de Ramon. 20 km further east is the Cordillera of the Andes with its mountain ranges and volcanoes, many of which exceed 6,000 m (19,685.04 ft) and in which some glaciers are maintained. The higher the Tupungato volcano with 6570 meters, located near the volcano Tupungatito of 5913 meters of altitude. To the northeast lie Lead Hill (5,424 meters) and Nevado El Plomo 6070 meters in altitude. To the southeast of the capital, meanwhile, are located on the Nevado Piuquenes (6,019 meters) volcano San Jose (5,856 m) and the volcano Maipo (5,323 m). From these peaks, the Tupungatito as San José and Maipo are active volcanoes.