Perbakti is an eroded 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...

 at the west of Mount Salak

Mount Salak

Mount Salak is an eroded volcanic range in West Java, Indonesia. Several satellite cones occur on the southeast flank and on the northern foot. Two craters are found at the summit. Mount Salak has been the site of a geothermal exploration.. The name Salak is come from salak fruit.- See also :*...

 in West Java

West Java

West Java , with a population of over 43 million, is the most populous and most densely populated province of Indonesia. Located on the island of Java, it is slightly smaller in area than densely populated Taiwan, but with nearly double the population...

, Indonesia

Indonesia

Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

. The summit is elongated in a northwest-southwest direction, in which Gunung Endut volcano rises above a saddle of Perbakti. Two 2 km wide of depressions on the northern and the southern side has formed two rivers, the Kaluwung Herang and Pamatutan rivers. Fumarole

Fumarole

A fumarole is an opening in a planet's crust, often in the neighborhood of volcanoes, which emits steam and gases such as carbon dioxide, sulfur dioxide, hydrochloric acid, and hydrogen sulfide. The steam is created when superheated water turns to steam as its pressure drops when it emerges from...

s, mud pots and hot spring

Hot spring

A hot spring is a spring that is produced by the emergence of geothermally heated groundwater from the Earth's crust. There are geothermal hot springs in many locations all over the crust of the earth.-Definitions:...

s are located on the south and the southeast flanks.