Baetic System
The main mountain ranges of Andalusia are the Sierra Morena and the Baetic System, consisting of the Subbaetic and Penibaetic Mountains, separated by the Intrabaetic Basin. In the north, the Sierra Morena separates Andalusia from the plains of Extremadura and Castile–La Mancha on Spain's Meseta Central. To the south the geographic subregion of Upper Andalusia lies mostly within the Baetic System, while Lower Andalusia is in the Baetic Depression of the valley of the Guadalquivir.