 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.