Bukit Bibinoi (Bibinoi Hill) is the largest and SE-most of a group of three andesitic Holocene stratovolcanoes located along a NW-SE line near the SE tip of Bacan Island, west of the southern tip of Halmahera (Yasin, 1980). The smaller Songa and Lansa volcanoes straddle a narrow isthmus separating the SE-most peninsula of Bacan Island from the Sibela Mountains metamorphic complex. The group lies along the same trend as the Amasing volcano group, located to the NW on the other side of the Sibela Mountains.