How many active volcanoes does Indonesia have ?
< onlyinclude > The geography of Indonesia is dominated by volcanoes that are formed due to subduction zones between the Eurasian plate and the Indo-Australian plate . < / onlyinclude > 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 years before present which was responsible for six years of volcanic winter , and Mount Tambora for the most violent eruption in recorded history in 1815 .