Ecuador is a country in northwestern South America, bordered by Colombia on the north, Peru on the east and south, and the Pacific Ocean on the west. The capital is Quito, located in a high mountain valley on the foothills of the Pichincha volcano. Ecuador also includes the Galápagos Islands in the Pacific. Depending on the currents in the sea and the coastal plain La Costa is arid or fertile, then the mountain ridge of the Andes follows. To the east there are foothills becoming the plains of the Amazon Basin, covered by rain forest, draining toward the Amazonas. The South American Plate collides with the Pacific Plate causing the subduction of the Pacific Plate with a deep trench in front of the coast. The orogeny of the Andes is called La Sierra and is spotted by the volcanoes of the "ring of fire", the Cotopaxi in Ecuador is one of the world's highest active volcanos. It is divided into three parallel mountain ridges, formnig an S-shape from north to south: the western, central (Cordillerra Real) and eastern (Cordillera Occidental) cordilleras.