Northern Sierra Madre Natural Park

Northern Sierra Madre Natural Park is the largest protected area in the Philippines, spanning 359,486 hectares across Isabela, Cagayan and Aurora provinces on eastern Luzon, with its core in Palanan, Isabela. Encompassing the northern Sierra Madre mountain range, primary lowland forests, and Pacific coastline, it is noted for exceptional biodiversity, including the Philippine eagle and other endemic species, and for protecting watersheds and habitats of indigenous Agta communities.

Visitors can expect a vast, remote protected landscape of primary lowland evergreen forest, rugged Sierra Madre mountains, rivers and Pacific coastline. The park is largely undeveloped with dense forest cover, limited trails and basic ranger facilities. Exploration is typically guided and focuses on nature observation, forest trekking, birdwatching and coastal areas around Palanan and Divilacan. Access requires coordination and travel by boat or chartered light aircraft due to isolation.