Page "Geography of the Philippines" Paragraph 18

The islands typically have narrow coastal plains and numerous swift-running streams.

Every island has sand beaches, but few open onto spacious lowlands.

There are few large plains or navigable rivers.

The longest river is the Cagayan River or Rio Grande de Cagayan in northern Luzon measuring 354 kilometers.

In Mindanao, the longest river is the Mindanao River or Rio Grande de Mindanao which drains Maguindanao and other parts in western-central Mindanao.

Agusan River drains eastern Mindanao.