Mount Pulong Bato is a monolith

Monolith

A monolith is a geological feature such as a mountain, consisting of a single massive stone or rock, or a single piece of rock placed as, or within, a monument...

 located in Zamboanga City

Zamboanga City

The City of Zamboanga : is a highly urbanized, independent and a chartered city located in Mindanao, Philippines....

 at the Zamboanga Peninsula

Zamboanga Peninsula

Zamboanga Peninsula / Western Mindanao is a peninsula and an administrative region in the Philippines. Designated as Region IX, the region consists of three provinces, namely, Zamboanga del Norte, Zamboanga del Sur, and Zamboanga Sibugay, its component cities of Dipolog, Dapitan, Pagadian, and...

, the western tip of the island of Mindanao

Mindanao

Mindanao is the second largest and easternmost island in the Philippines. It is also the name of one of the three island groups in the country, which consists of the island of Mindanao and smaller surrounding islands. The other two are Luzon and the Visayas. The island of Mindanao is called The...

 in the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

. The mountain is situated in the Upper Abong-Abong Park, in Barangay

Barangay

A barangay is the smallest administrative division in the Philippines and is the native Filipino term for a village, district or ward...

 Pasonanca, only a few kilometers away from the city's downtown section.

Geology

Pulong Bato became infamous because when the Philippine Institute of Volcanology and Seismology

Philippine Institute of Volcanology and Seismology

The Philippine Institute of Volcanology and Seismology is a Philippine national institution dedicated to provide information on the activities of volcanoes, earthquakes and tsunamis, as well as other specialized information and services primarily for the protection of life and property and in...

 (PHIVOLCS) confirmed the mountain is a volcano which is unknown to most people. What is unusual about the mountain is, unlike the other mountains surrounding the city, only Mt. Pulong Bato is made from solid rock.
According to PHIVOLCS, the volcano is an Intrusion

Intrusion

An intrusion is liquid rock that forms under Earth's surface. Magma from under the surface is slowly pushed up from deep within the earth into any cracks or spaces it can find, sometimes pushing existing country rock out of the way, a process that can take millions of years. As the rock slowly...

 type of volcano meaning it was formed within earth's crust. Magma was pushed from the beneath the earth surface but did not come out through an eruption like a typical volcano (Extrusion). The magma eventually solidified while it is still enclosed by softer rocks, which was later exposed by erosion or weathering, a process that could take thousands of years.

Holy Week observance

The mountain is near the premises of the famous Abong-Abong Park, where both domestic and foreign catholic devotees pilgrimage annually during Holy Week

Holy Week

Holy Week in Christianity is the last week of Lent and the week before Easter...

to observe the holiday and meditate.