Mount Bombalai is part of a volcanic field

Volcanic field

A volcanic field is an area of the Earth's crust that is prone to localized volcanic activity. They usually contain 10 to 100 volcanoes, such as cinder cones and are usually in clusters. Lava flows may also occur...

 on the Semporna peninsula

Semporna peninsula

The Semporna peninsula is a Peninsula located on the southwest of Darvel Bay and to the northeast of Sebatik Island. During the Last Ice Age , the peninsula was actually connected with the great Bridge of island of Mindanao, Philippines where the active Volcano named Jolo is located at and where...

 in northeastern Borneo

Borneo

Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....

. The volcano lies in Tawau Division

Tawau Division

Tawau Division is one of the five administrative sub-divisions of Sabah, east Malaysia, on the island of Borneo. It occupies a total of 14,905 square kilometers or 20% of Sabah's territory...

, Sabah

Sabah

Sabah is one of 13 member states of Malaysia. It is located on the northern portion of the island of Borneo. It is the second largest state in the country after Sarawak, which it borders on its southwest. It also shares a border with the province of East Kalimantan of Indonesia in the south...

, Malaysia across Cowie Harbour from the Indonesian province of East Kalimantan

East Kalimantan

East Kalimantan is the second largest Indonesian province, located on the Kalimantan region on the east of Borneo island. The resource-rich province has two major cities, Samarinda and Balikpapan...

, and is the only volcano in the country. The low volcanic cone is located north of Sebatik Island

Sebatik Island

Sebatik Island is an island off the eastern coast of Borneo, partly within Indonesia and partly within Malaysia. It has an area of approximately 452.2 square kilometres...

 and has a roughly 300-m-wide crater breached to the south. Two young lava flows extend almost to the coastal plain. The flows were considered younger than a lava flow radiocarbon dated at about 27,000 years before present, and the extrusion of basaltic lavas possibly continued into Holocene

Holocene

The Holocene is a geological epoch which began at the end of the Pleistocene and continues to the present. The Holocene is part of the Quaternary period. Its name comes from the Greek words and , meaning "entirely recent"...

time. This marks the only known area of possible Holocene volcanism on Borneo. It is also known to be Malaysia's highest volcanic point.