Honsawa Hot Spring WildBath
Hot Spring Overview
Japan’s Highest Outdoor Hot Spring “Unjō no Yu” is located in Honsawa Onsen.
"Unjō no Yu" is a natural hot spring that continuously flows in the midst of untouched nature. On clear days, you can enjoy views of Mount Iō from the bath.
In addition to “Unjō no Yu,” which sits at an altitude of 2,150 meters—the highest outdoor hot spring in Japan—you can also enjoy another natural hot spring with a different mineral composition, called “Koke-momo no Yu.”
"Unjō no Yu" is a mixed-gender bath without a changing room, but wearing a swimsuit is allowed.
At the source, Honsawa Onsen, you can stay overnight in the lodge or camp in a tent.
About Secluded Rating
Total Score
超秘湯
Access
Scenery
Value
You can experience a natural, free-flowing hot spring in the heart of the wilderness.
Access is only by foot, and we have rated it a "5" for its secluded nature.
From this hot spring, it is also possible to hike to Mt. Iō (Ioudake) and Mt. Aka (Akadake) via the Honsawa Trailhead.
Honsawa Onsen is accessible only on foot.
You must drive or take a taxi to the Honsawa Entrance, and from there, it takes about 2 to 2.5 hours on foot.
There is a 4WD parking area located further in; if starting from there, it takes about 1 hour on foot to reach the hot spring.
Hot Spring Details
| Quality | 硫黄泉 カルシウム・マグネシウム-硫酸塩泉 |
| Temp | 45℃ ～ 60℃ |
| Flow | Natural Source Flow |
| pH | pH 2.3  0714 AcidicNeutralAlkaline |
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Temperature
Flow Type
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Practical Info
| Stay | OK | ||||||||||||||||||
| Day Trip | OK | ||||||||||||||||||
| Fee | Adult 1000JPY/Child ---JPY | ||||||||||||||||||
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| Mon | Tue | Wed | Thu | Fri | Sat | Sun | Hol | |
|---|---|---|---|---|---|---|---|---|
| 05:00 - | ◯ | ◯ | ◯ | ◯ | ◯ | ◯ | ◯ | ◯ |
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Access Information
Map
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