The Zona Sur (Southern Zone) is one of the five natural regions on which CORFO divided continental Chile in 1950. Its northern border is formed by the Bío-Bío River, the limit with the Central Chile Zone. By west with the Pacific Ocean, by the east with the Andean mountains and Argentina. Its southern border is the Chacao Channel, beyond it lies the Austral Zone. While Chiloé Archipelago belongs geographically to Zona Austral in terms of culture and history it lies closer to Zona Sur.