The Sistema Ibérico extends from the Cordillera Cantábrica southeastward and, close to the Mediterranean, spreads out from the Río Ebro to the Río Júcar. The barren, rugged slopes of this mountain range cover an area of close to 21,000 square kilometers. The mountains exceed 2,000 m in their northern region and reach a maximum height of over 2,300 m east of the headwaters of the Rio Duero. The extremely steep mountain slopes in this range are often cut by deep, narrow gorges.