community-forum community-penpal community-userReports destinations-admission destinations-beenThere-solid destinations-bookmark-solid destinations-city_outline destinations-city_solid destinations-closedDays destinations-date destinations-getThere destinations-hotels destinations-hoursFees destinations-itineraries-3 destinations-nearbySpots destinations-pin-simple-outline destinations-pin-simple destinations-sortBy-dots destinations-tours destinations-town interests-agriculture interests-amusementParks interests-beaches interests-castles interests-city_solid interests-contemporaryArt interests-events interests-festivals interests-flowers interests-foodDrink interests-gardens interests-hiking interests-historicSites interests-industry interests-koyo-single interests-koyo interests-mangaAnime interests-museums interests-nature interests-onsen interests-parks interests-pottery interests-sakura-single interests-sakura interests-scenicRides interests-shopping interests-shrines interests-skiing interests-snow interests-sumo interests-temples interests-traditionalArts interests-traditionalTheater interests-viewpoints interests-volcanoes interests-wildlife interests-winterIlluminations news-section planning-tickets-2 planning-transportation-access planning-transportation-bicycle planning-transportation-boat planning-transportation-bus planning-transportation-car planning-transportation-plane planning-transportation-shinkansen planning-transportation-tickets planning-transportation-train planning-transportation-walk shapes-chevron-down shapes-circle shapes-star social-fb social-gplus social-instagram social-twitter social-youtube ui-alert-construction ui-alert-warning ui-calendar ui-confirmed-outline ui-confirmed-solid ui-date ui-globe ui-lightbulb ui-no_entry ui-ok ui-pencil ui-reverse ui-search ui-time ui-video-play ui-x user-avatar

Iozan (R, Iōzan, lit. "Sulfur Mountain") is an active volcano in the vicinity of Kawayu Onsen. Its yellow, sulfurous vents can be viewed from a close proximity as visitors are free to walk around the steaming, smoking area. Eggs, cooked by the natural heat of the mountain, are usually on sale near the vents. Further refreshments are available from the Iozan Visitor Center.

A few nice trails offer pleasant walking around the mountain. The longest path (2.5 kilometers) leads to the visitor center of nearby Kawayu Onsen. This flat, well maintained route passes through the shrub and low brush area around Iozan before moving into forest area in Kawayu Onsen.


Iozan stands outside of the hot spring resort of Kawayu Onsen. The area with the volcanic activity, is less than five minutes from the town center by car. On foot, you can get there in about 45 minutes from the town center or in about 20 minutes from Kawayu Onsen Station.

From mid July to early October (July 15 to October 9, 2017), infrequent buses between Lake Mashu, Kawayu Station, Kawayu Onsen, Lake Kussharo and Bihoro Pass make a stop at Mount Iozan. During the rest of the year, there is no bus service.

How to get to and around Akan National Park

Page last updated: June 13, 2017