Mount Bunagatake is the highest mountain of Hira Mountains. Hira mountains consist of three parts, Oku-Hira, Kita-Hira and Minami-Hira, literally, ‘Deep Hira', ‘North Hira', and ‘South Hira'. Mount Bunagatake belongs to Oku-Hira, and on the Mesozoic strata as other mountains of Oku-Hira.