The geography of Indonesia is dominated by volcanoes that are formed due to subduction zones between the Eurasian plate and the Indo-Australian plate. Some of the volcanoes are notable for their eruptions, for instance, Krakatau for its global effects in 1883, Lake Toba for its supervolcanic eruption estimated to have occurred 74,000 Before Present which was responsible for six years of volcanic winter, and Mount Tambora for the most violent eruption in recorded history in 1815.
Mount Merbabu is a dormant stratovolcano in Central Java province on the Indonesian island of Java. Loosely translated, Gunung Merbabu could mean 'Mountain of Ash' from the Indonesian word babu. The active volcano Mount Merapi is directly adjacent on its south-east side, while the city of Salatiga is located on its northern foothills. A 1,500 m high broad saddle lies between Merbabu and Merapi, the site of the village of Selo and highly fertile farming land.
There are two peaks; Syarif (3,119 m) and Kenteng Songo (3,145 m). Three U-shaped radial valleys extend from the Kenteng Songo summit in northwesterly, northeastly and southeastly directions.
Two known moderate eruptions occurred in 1560 and 1797 and were rated 2: Explosive, on the Volcanic Explosivity Index. An unconfirmed eruption may have occurred in 1570.
Geologically recent eruptions originated from a North Northwest-South Southeast fissure system that cut across the summit and fed the large-volume lava flows from Kopeng and Kajor craters on the northern and southern flanks, respectively.
Merbabu can be climbed from several routes originating from the town of Kopeng on the north east sideside, and also from Selo on the southern side. A climb from Kopeng to Kenteng Songo takes between 8 and 10 hours.