Cordillera Central (Luzon) Sierra Madre Mountains, the longest mountain range in the country, through the Caraballo Mountains in Nueva Vizcaya province. During Spanish colonial period, the whole range was called "Nueva Provincia", (New Province). The Cordillera Central is the highest mountain range in the Philippines. It comprises about 1/6 of the whole Luzon island with a total area of . The highest mountain in the range, Mount Pulag, is also the highest mountain on Luzon Island at . It is officially the third highest mountain in the country after Mount Dulang-dulang and Mount Apo on Mindanao Island, the second largest island of the
Mount Apo mountain forests. A portion of the eastern slopes are also within the scope of the UNESCO Hydrology Environment Life and Policy (HELP) Network. The Davao HELP Network is focused on building collaboration among watershed stakeholders. In March 2015, it was taken out from the UNESCO List of Tentative Sites due to the dramatic changes (such as logging, intrusion of companies and urban and agricultural landscape, exploitation, and poaching, among others) it experienced which does not constitute the UNESCO documents that describes the park. Better conservation and a change in the content of documents was recommended by UNESCO. Mt. Apo generally