Mount Bulusan, or Bulusan Volcano, is the southernmost volcano

Volcano

2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...

 on Luzon

Luzon

Luzon is the largest island in the Philippines. It is located in the northernmost region of the archipelago, and is also the name for one of the three primary island groups in the country centered on the Island of Luzon...

 Island in the Republic of the Philippines. It is situated in the province of Sorsogon

Sorsogon

Sorsogon is a province of the Philippines located in the Bicol Region; it is the southernmost province in Luzon and is subdivided into fourteen municipalities and one city. Its capital is Sorsogon City and borders the province of Albay to the north...

 in the Bicol

Bicol Region

The Bicol Region or Bicolandia is one of the 17 regions of the Philippines. Its regional center is Legazpi City...

 region, 70 km (43.5 mi) southeast of Mayon Volcano

Mayon Volcano

Mayon Volcano, also known as Mount Mayon, is an active volcano in the province of Albay, on the island of Luzon in the Philippines. Renowned as the "perfect cone" because of its almost symmetric conical shape, Mayon forms the northern boundary of Legazpi City, the largest city in terms of...

 and approximately 250 km (155.3 mi) southeast of the Philippine capital of Manila.

It is one of the active volcanoes in the Philippines

Active volcanoes in the Philippines

Active is commonly termed for volcanoes with historical eruptions. Moreover, the Philippine Institute of Volcanology and Seismology classify active volcanoes in the country as having erupted within historical times , with accounts of these eruptions documented by man; or having erupted within the...

.
Bulusan is classified by volcanologists as a stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 (composite volcano) and covers the northeast rim of Irosin caldera

Caldera

A caldera is a cauldron-like volcanic feature usually formed by the collapse of land following a volcanic eruption, such as the one at Yellowstone National Park in the US. They are sometimes confused with volcanic craters...

 that was formed about 40,000 years before present.