Extinct Volcanic Hills in Batangas Province

The Province of Batangas is part of the so-called Macolod Volcanic Corridor¹, a 40-kilometer wide system of volcanism extending from Batangas Bay in the southwest to its northern edge off Laguna de Bay in what is known as the Jalajala Peninsula.

In this corridor are active, potentially active and inactive volcanoes. Some are fairly known landmarks in both Batangas and Laguna because of their size: Mt. Batulao in Nasugbu, the Malepunyo Range east of Lipa City, and Mt. Makiling in Laguna as well as Mt. Banahaw in Quezon Province. All of these are classified as stratovolcanoes.

There are also some 200 smaller volcanoes called cinder or scoria cones and maars within the corridor, and it is to the former, i.e., the cinder or scoria cone, that this article is dedicated.

These cinder or scoria cones are the most common of the volcano types. They tend to be small, mostly less than 300 meters in height. Many of these, particularly those in Batangas Province, are probably what are called “monogenetic volcanoes.” This means that they only erupt once², after which they become extinct.

Some of these are inactive and likely extinct cinder or scoria cones in Batangas are described below, primarily because they are within municipal or city boundaries and are, therefore, familiar to local populations.

Anilao Hill (Lipa City)

Before it was quarried, Anilao Hill, south of Poblacion, Lipa in the barrio of Anilao, had a recorded height of 358 meters or 1,175 feet. It is basaltic in nature, basalt being “rock made from the rapid cooling of lava on the Earth’s surface³.” Its estimated last eruption was sometime during the Pleistocene Period or, at the most recent, some 11,700 years ago⁴. The hill is significant historically because of Japanese defenses set up on the hill in World War II. A guerrilla reported noted that “around 200 Japs were stationed on the hill with anti-aircraft guns⁵.”

Bigain Hill (San Jose)

Bigain Hill is located almost equidistant between the municipalities of San Jose and Cuenca, although it is part of the former’s territory. It is recorded to be some 113 meters or 371 feet above the surrounding terrain and 0.91 kilometers wide. An archived PHIVOLCS list of inactive volcanoes in the Philippines includes Bigain Hill, but gives no other information beyond its location. Its composition and last eruption are unknown.

Sorosoro Hill

Sorosoro Hill is a mound of earth on the outskirts of Batangas City. Phivolcs does NOT list Sorosoro Hill among the inactive volcanoes in Batangas, but the book “The Soils of the Philippines⁶” considers it one of several pyroclastic cones part of the so-called Macolod Volcanic Cooridor. Geoview states its elevation as 106 meters or 348 feet⁷. Similar to Anilao Hill in Lipa City, Sorosoro Hill was also used by the Japanese for military installations during World War II, taking advantage of the elevation that it provided. No information can be obtained about its soil composition.

Tombol Hill

Tombol Hill is seen prominently from the adjacent poblacion of the Municipality of Rosario. It is included in the archived PHIVOLCS list of inactive volcanoes in the Philippines. “The Soils of the Philippines” suggests that, like the Anilao Hill, it is a pyroclastic cone part of the Macolod Volcanic Corridor. The hill is said to have a height of 235 meters or 771 feet⁸.

The Active Cone

While all of the preceding hills are inactive, possibly even extinct, as volcanoes, it has to be mentioned that Taal Volcano, which is still very much active and whose last major eruption was as recent as 2020, has vents which are also considered cinder or scoria cones. What is called Vulcan Point in the Main Crater Island of Taal Volcano, for instance, is in fact a cinder cone⁹. Since government has banned settling on the crater island in the aftermath of the 2020 eruption, the danger to human populations has been greatly mitigated. Taal’s historical eruptions, after all, had been known to kill people by the hundreds.

¹ “The Macolod Corridor: A Rift Crossing the Philippine Island Arc,” by Ulrich Knittel, Marc J. Defant, Hansgeorg Förster, Dietmar Oles and Ronnie C. Torres, published November 1990 in Tectonophysics.
² “How Volcanoes Work: Scoria Cones,” author and date of publication unknown, online at the San Diego State University College of Sciences.
³ “Basalt Definition, Composition & Uses,” by Megan Mathis, online at Study.com.
⁴ “Anilao Hill,” online at the Smithsonian Institution National Museum of National History Global Volcanism Program. ⁵ “Luansing Unit, Fil-American Batangas Guerrillas,” File No. 63, downloaded from PVAO.
⁶ “The Soils of the Philippines,” by Rodelio B. Carating, Raymundo G. Galanta and Clarita D. Bacatio.
⁷ “Sorosoro Hill,” online at Geoview.info.
⁸ “Tombol Hill, Rosario, Batangas,” online at The Rosario Batangas.
⁹ “The Taal Volcano in the Philippines,” online at Vulkane.net.