There are three large mountain ranges in Luzon-the Caraballo del Sur, the Sierra Madre, and the Caraballo de Baler. The Caraballo del Sur extends from north to south and consists of the Central Cordillera and the Northern Cordillera. Its highest peak is at the intersection of the boundaries of Abra, Ilocos Norte, and Cagayan.
The Sierra Madre, also known as the Pacific Coast Range, begins at the town of Baler, and crosses the provinces of Cagayan, Isabela, Nueva Viscaya, and Quirino. The Sierra Madre is the longest continuous mountain range in the Philippines.
The Caraballo de Baler extends from Baler, the capital of Aurora, and ends in the San Bernardino Strait at the southeastern tip of Luzon. In this ranges are found Mayon Volcano in Albay and Bulusan Volcano in Sorsogon.
Also in Luzon are the smaller mountain ranges of Zambales and Tagaytay. The Zambales Range begins at Cape Bolinao in Pangasinan, extends south along the coast of the China Sea, and ends in the Bataan provinces of Cavite and Batangas. Mount Makiling, in Laguna, and Taal Volcano in Batangas, are in the Tagaytay Range.
In Visayan area, Panay Island has a range stretching from north to south and separating the province of Antique from Aklan, Iloilo, and Capiz provinces.
The Principal Mountain Ranges in Mindanao
• Diwata Mountains – run along the eastern coast of the island.
• Central Range – extends through the length of Mindanao following the western boundary of the Agusans and the Davaos.
• The mountain ranges which form the backbone of the Zamboanga peninsula and Misamis Occidental.
The highest peak in the Philippines is Mount Apo, in Davao del Sur, 2,954 meters above the sea level. The second highest is Mount Pulog in the Bicol Peninsula, about 2,585 meters above the sea level. Other notable Philippine mountain peaks are Makiling, Banahaw, and San Cristobal-all in Laguna-Arayat in Pampanga, Mayon in Albay, Baco in Mindoro Occidental, Matalingajan in Palawan, and Makaturing in Lanao del Sur.
The River Systems
The main river systems in Luzon are the following;
• Rio Grande de Cagayan – drains the Cagayan Valley
• Agno River – drains the rivers in Nueva Ecija, Pangasinan and Tarlac.
• Abra River – receives its tributaries from Cordillera and drains Lepanto, Bontoc and Abra.
• Pampanga River – drains the rich valleys of Nueva Ecija, Pampanga and Bulacan
The largest river system in the Philippines is Rio Grande de Mindanao. It is fed by the waters of two large lakes and drains the central Mindanao basin.