Overview
The Sierra Madre is the longest mountain range in the Philippines. Spanning for over 540 kilometers, it runs from the province of Cagayan down to the province of Quezon, forming a north–south direction on the eastern portion of Luzon.
Description
The Cordillera Central, the central mountain chain of Luzon, running north to the Luzon Strait from the northern boundary of the central plain, is the most prominent range. It consists of two and in places three parallel ranges, each with an average elevation of about 5,900 feet (1,800 metres). The Sierra Madre, extending along the Pacific coast from northern to central Luzon, is the longest mountain range in the country. That range and the Cordillera Central merge in north-central Luzon to form the Caraballo Mountains. To the north of the latter, and between the two ranges, is the fertile Cagayan Valley. The narrow Ilocos, or Malayan, range, lying close along the west coast of northern Luzon, rises in places to elevations above 5,000 feet (1,500 metres) and is seldom below 3,500 feet (1,000 metres); it is largely volcanic. In the southwestern part of northern Luzon are the rugged Zambales Mountains, consisting of more or less isolated old volcanic stocks (rock formed under great heat and pressure deep beneath the Earth’s surface).
Most of the central plain of Luzon, about 150 by 50 miles (240 by 80 km), is only about 100 feet (30 metres) above sea level. The greater part of southern Luzon is occupied by isolated volcanoes and irregular masses of hills and mountains. The highest peak is Mayon Volcano (8,077 feet [2,462 metres)]), near the city of Legaspi (Legazpi) in Albay province on the island’s Bicol Peninsula in the southeast.