Cagayan Valley is the large mass of land in the northeastern region of Luzon, comprising the provinces of Cagayan, Isabela, Nueva Vizcaya, Quirino, and the Batanes group of islands. It is bordered to the west by the Cordillera mountain range, to the east by the Sierra Madre, to the south by the Caraballo Mountains, and to the north by the Luzon Strait.