Mount Io

Mount Io is an active volcano in Kokonoe featuring a height of about 1580 meters (5180 feet) with two explosion craters and a lava dome. The mountain belongs to the Akan Volcanic Complex and shows clear signs of its volcanic origin in its physical structure.

The mountain's geological formation began over 240,000 years ago as part of the region's volcanic development. Recorded eruptions started around 850 AD and continued periodically, with the last major activity occurring in 1936.

The Ainu people, indigenous to the region, named this mountain Atosa-nupuri, meaning bare mountain, reflecting how volcanic activity constantly reshapes its slopes. This naming tradition shows how the local community understood and lived with the volcano's ongoing influence.

Multiple bus services connect the mountain to surrounding cities, making access straightforward from nearby towns. A visitor center at the base provides information about volcanic geology and helps guide visitors along designated trails.

The slopes contain fumaroles that release sulfurous steam, creating unusual growing conditions found nowhere else in the region. These openings in the mountain allow specialized alpine plants to thrive in what would normally be barren rock.