Cagayan River

The Cagayan River, also known as the Rio Grande de Cagayan, is the longest river in the Philippines and the largest river by discharge volume of water (followed by Rio Grande de Mindanao). It has a total length of approximately 350 kilometres (220 mi) and a drainage basin covering 27,753 square kilometres (10,715 sq mi). It is located in the Cagayan Valley region in northeastern part of Luzon Island and traverses the provinces of Nueva Vizcaya, Quirino, Isabela and Cagayan.