Cagayan River or Rio Grande de Cagayan, with a total length of 353 kilometers, is the longest and widest river in the Philippines. It bisects the Cagayan Valley from north to south. Also considered as the mightiest watercourse, Cagayan River sources its water from smaller rivers and streams in the mountain ranges of Sierra Madre, Caraballo, Cordillera, and Balete Pass. This river meets the South China Sea in an impressive expanse known as Aparri Delta. The other notable rivers in Luzon are Chico, Abra, Pampanga, and Bicol. In the south, the principal rivers are Mindanao (known in its upper course as the Pulangi) and Agusan. Meanwhile, the underground river of St. Paul's Natural Park in Palawan is considered as one of the world's longest subterranean rivers.
Cagayan River or Rio Grande de Cagayan
