Once a site of sulfur mining, it is one of most active volcanos in Akan-Mashu National Park and visitors can see close up views of steam vents with brilliant yellow sulfur crystals. At the foot of the volcano, alpine plants such as Japanese Stone Pine, Labrador Tea and Crowberry are dominant even though the altitude is as low as 150 m (492 ft) above sea level which is due to harsh environment because of the volcanic gas and poor soil. Labrador Tea flowers bloom from late June to early July and visitors can enjoy the 2.5 km (1.6 mi) nature trail between Mt. Io and Kawayu Onsen village with little white flowers all around.
The source of the high-quality hot spring in Kawayu Onsen village is created at Mt. Io and flows to the village under the nature trail.
Entering Mt. Io is strictly prohibited. However, a unique hiking tour leading to an enormous crater and sulfur mining sites can be taken but only with a certified guide. You’ll be impressed by the Mar’s like view on the mountain. You need to be fit and have suitable shoes and clothing for hiking since part of the trail is steep, rocky, and unstable.
Please visit the link below (only Japanese so far) for more information and reservations. Let us know if you have any questions.
https://masyuko.or.jp/enjoy/atosanupuri_trekking_tour/
