Gunung Sumbing, Stratovolcano in Temanggung, Central Java, Indonesia

Gunung Sumbing is a stratovolcano in Central Java that rises 3,371 meters (11,060 feet) above sea level and is characterized by a symmetrical cone shape with an 800-meter (2,625 feet) wide crater at its summit. The crater contains sulfur gases and mud pools that can be seen by hikers when reaching the top.

The last documented volcanic activity occurred in 1730 and led to the formation of a small phreatic crater at the summit. Since then the volcano has shown only occasional steaming without new eruptions.

Locals in Temanggung, Wonosobo and Magelang call Sumbing the twin of Mount Sindoro, since the two cones face each other across the Kledung Pass, the provincial road between Temanggung and Wonosobo. The name Sumbing is also used for two other Indonesian mountains, in Aceh and Jambi.

The approximately 14-kilometer round trip hike is normally spread over two days, with starting points accessible from Semarang or Yogyakarta. Certified mountain guides are available for accompaniment and help with orientation on the different routes.

The mountain forms the meeting point of three major river basins: Progo, Serayu and Bogowonto, all of which flow to the Indian Ocean. This geographic feature makes it an important watershed for the entire Central Java region.