The Andes form the world's longest exposed mountain range. They lie as a continuous chain of highland along the western coast of South America. The range is over 7,000 km (4,400 miles) long, 200-700 km (300 miles) wide (widest between 18° to 20°S latitude), and of an average height of about 4,000 m (13,000 ft). The Andean range is composed principally of two great ranges, the Cordillera Oriental and the Cordillera Occidental, often separated by a deep intermediate depression, in which arise other chains of minor importance, the chief of which is Chile's Cordillera de la Costa.