Mount Iō

Mount Iō is an active volcano in Mishima composed of rhyolitic rock that rises to 704 meters above sea level. The landscape features numerous vents where volcanic gases continuously escape, creating a visibly dynamic and geologically active terrain.

The volcano formed as part of the Kikai Caldera system and remains geologically active, with recorded volcanic activity documented through 2013. Its ongoing activity demonstrates the continued geological dynamics of the Kagoshima region.

Local residents and visitors recognize the mountain for its sulfurous vents and steaming activity, which shape how people experience and relate to this landscape. The continuous release of volcanic gases creates a distinctive sensory experience that defines the place for those who visit.

Visitors should prepare for slippery paths and strong sulfur odors, making sturdy footwear and possibly a respirator mask advisable. The cooler months outside of summer provide the most comfortable conditions for exploring the slopes and vents.

The mountain's surface displays yellow sulfur crystal formations created by mineral deposits from the active vents. These crystals continuously reform as volcanic gases interact with the cooler air, making them visible evidence of the ongoing geological processes at work.

Location: Mishima

Elevation above the sea: 704 m

Made from material: rhyolite

Part of: Kikai Caldera

GPS coordinates: 30.79301,130.30526

Latest update: December 14, 2025 14:26