Sierra Morena (syā´rä mōrā´nä), mountain range, SW Spain, extending c.375 mi (600 km) eastward along the southern edge of the Meseta (central plateau) from the Portuguese border to the Sierra de Alcaraz. Its highest peak is Bañuelo (c.4,340 ft/1,320 m). Partly forested with oak and chestnut trees, the range is also rich in a great variety of minerals, including copper, lead, and coal. The Sierra Morena is crossed by highways and railroads built to take the minerals out of the region. The Despeñaperros Pass is the main route through the mountains, linking Castile and Andalusia.