Mount Arayat

Lore & Background

Mount Arayat has a breached crater on its northwest side with a smaller andesitic dome in the collapse amphitheater. Historical records of eruption exist, but the only dated rocks are 530- and 650-thousand-year-old basalts predating the collapse and formation of the lava dome. Weak steam activity is currently present at some heavily eroded vents on the northwestern face of the summit. PHIVOLCS classifies it as potentially active, but there are no confirmed historical eruptions within the last 2,000 years.

During the Philippine Revolution, revolutionaries retreated to Mount Arayat after the failure of the Cry of Nueva Ecija in September 1896. In September 1897, Gen. Francisco Macabulos retreated southeast to the mountain to avoid capture. During World War II, American guerrilla Colonel Thorpe was captured by Imperial Japanese forces on Mount Arayat on December 10, 1942. The mountain was later used as a hiding place for communist Filipino guerrillas called the Hukbalahap.

In folklore, Mount Arayat is said to be the home of the god/sorcerer Sinukuan/Sinukwan or Sucu, who lives at White Rock. The mountain is believed to have been relocated from a swamp due to a great flood or as punishment for the inhabitants' misdeeds. Sinukuan's only real rival is Namalyari of Mount Pinatubo.

Reader's Guide

Mount Arayat stands as a distinct landmark in the Central Luzon plain, serving both as a natural monument and a site of historical refuge. Its significance spans geological, historical, and cultural dimensions. Geologically, it is a potentially active stratovolcano with a breached crater and a lava dome called White Rock, which may have formed in the last 2,000 years. The mountain's eruptions are hypothesized to have rerouted the Pampanga River. Historically, it provided shelter to revolutionaries during the Philippine Revolution and to guerrillas during World War II, including the Hukbalahap. Culturally, it is central to local folklore as the home of the deity Sinukuan. The mountain's name has multiple etymological theories, including origins from a Spanish encomiendero, the dry season rice crop, or the word for 'east.' Despite its protected status as a national park, Mount Arayat is currently under immense deforestation threat. Its flora includes the recently discovered plant species Pyrostria arayatensis, described in 2020.

Did You Know?

• Mount Arayat was officially declared a national park in 1933.
• The only dated rocks from Mount Arayat are 530- and 650-thousand-year-old basalts.
• During World War II, American guerrilla Colonel Thorpe was captured by Japanese forces on Mount Arayat on December 10, 1942.
• A plant species, Pyrostria arayatensis, discovered on Mount Arayat, was formally described in 2020.

Geology & Volcanic Character

Mount Arayat rises as a solitary cone from the flat agricultural expanse of the Central Luzon Plain, reaching 1,026 metres above sea level. Despite local legends of multiple merged peaks, geological evidence confirms it as a single-cone stratovolcano composed primarily of basalt and andesite. Its most striking feature is a roughly 1.2-kilometre-wide crater that has partially collapsed along the western and northern rims, opening a breach toward the west-northwest. This collapse event generated a massive debris-avalanche deposit that still shapes the hummocky terrain on the mountain's western and northwestern flanks. Within the resulting amphitheater sits White Rock, an andesitic lava dome formed by post-collapse volcanic activity. The only precisely dated rocks on the mountain are basalts aged 530,000 and 650,000 years, both predating the dome's formation. An analysis report suggests the volcano may have erupted within the last two millennia, though no cultural records of historic eruptions survive. Today, faint steaming persists at heavily eroded vents on the northwestern summit face, a quiet reminder that the mountain remains potentially active.

Revolutionary and Wartime Sanctuary

During the Philippine Revolution, Mount Arayat became a refuge for fighters fleeing Spanish counter-attacks. After the failed uprising at Nueva Ecija in September 1896, revolutionaries withdrew to the mountain's slopes. The following year, General Francisco Macabulos led his troops southeast from Tarlac to the volcano to evade capture, engaging in several skirmishes before ultimately surrendering on January 15, 1898. Decades later, the mountain again sheltered those resisting occupation. In December 1942, American guerrilla Colonel Thorpe was seized by Imperial Japanese forces on its grounds. The Hukbalahap communist guerrillas subsequently used the mountain as a stronghold. Nicanor "Bapa" Songco orchestrated a plan to move his family and those of fellow guerrillas from Bulacan, Pampanga, and Nueva Ecija to the mountain's safety. When Japanese soldiers arrived and intercepted the group just before their ascent, Songco surrendered himself to spare everyone else. He was tortured—his skin flayed from his arm—before being released. He climbed back up to reunite with his family on the slopes.

A Name with Many Origins

The name "Arayat" carries layers of linguistic history that scholars have debated for centuries. The earliest Western record appears in the 1696 travel diary of Italian explorer Gemelli Careri, who noted that local people called the mountain "Bondo Kalaya," a form that later shifted to "Bondoc Alaya" before settling into the familiar "Arayat." Multiple competing explanations persist for the name's root. One traces it to Fernándo de Arayat, a Spanish encomiendero whose Spanish hometown bore the same name, with locals gradually reshaping the word into "Daya." Another links "Dayat" to the Tagalog term "dayatan," referring to dry-season rice cultivation or the irrigation of paddies during the dry months. A third theory holds that "Alaya" simply means "east," making "bunduk alaya" a straightforward descriptor for an eastern-facing mountain. A more speculative modern claim equates the peak with Mount Ararat of Genesis, though this ignores the well-documented Ararat near the Turkish-Armenian border. Some sources further distinguish "Aláya" as the mountain's name from "Aráyat" as the town's.

A Landmark at the Crossroads

Rising abruptly from the 15-to-35-metre Central Luzon Plain, Mount Arayat has long served as a geographic anchor for the surrounding region. Its southern half falls within the municipality of Arayat, while the northern slopes and summit belong to Magalang. The mountain sits just ten kilometres east of Angeles City and the former Clark Air Base, 26 kilometres east of the active volcano Mount Pinatubo, and 75 kilometres north of Manila. Recognizing its significance, the Philippine government declared it a national park in 1933 and later designated it a tourist destination in 1997. The peak supports unique biodiversity, including Pyrostria arayatensis, a Rubiaceae family plant discovered during botanical surveys by researchers from Angeles University Foundation and the University of Santo Tomas. White Rock, the andesitic dome within the crater, doubles as a research site for students at Pampanga State Agricultural University. Yet despite its protected status, the mountain now faces an immense threat from deforestation, putting both its ecological heritage and its geological integrity at risk.