A heartwarming chloride hot spring that springs up in peaceful satoyama
Nagano Saku City
"Fuse Onsen" is a day-use hot spring facility located in the peaceful countryside of Saku City, Nagano Prefecture. It features open-air baths with views of serene satoyama scenery right in front of you, as well as a spacious indoor bath, and has long been loved by locals. The water is colorless and clear, and is known as a sodium chloride hot spring that warms you thoroughly from the core and keeps you from cooling off easily. The sauna features a rotation system every week, with two types available: a blazing authentic dry sauna and a fragrant mist sauna that gently moisturizes the skin. It also pairs exceptionally well with the deep, mildly cool cold plunge bath and outdoor bathing while soaking up the satoyama breeze all over your body.
TypeNatural Hot Spring
This natural sodium chloride hot spring is highly praised for warming the body thoroughly, keeping you warm long after bathing, and making it hard to cool off afterward. Its mild weakly alkaline spring water is gentle on the skin, and in the open-air bath you can relax lavishly in a famous hot spring while enjoying the refreshing satoyama scenery that changes with the seasons.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity5people
A proper dry sauna with a comfortable old-fashioned atmosphere that makes the most of the warmth of wood. The temperature is kept high, and the strong, pleasant dry heat filling the room quickly warms you from the core and encourages refreshing sweating. The bathing areas for men and women switch every week.
Sauna TypeMist Sauna
Capacity6people
A gentle, easy-to-enter mist sauna where abundant warm steam spreads leisurely throughout the room. The high humidity makes it easy to breathe, and it softly moisturizes your skin, hair, and throat while warming you calmly and comfortably without putting strain on your body.
Water QualityTap Water
Capacity2people
A cold plunge bath installed right near the sauna room, featuring a distinctive deep design with no steps. The water temperature is set to be gentle on the body and not too cold, so even those who do not like the sudden shock of cold water can sink in comfortably and refresh their whole body pleasantly.
Closed Days: Open all year
384-2203 1228-1228 Fuse, Saku City, Nagano Prefecture
Gender Access
Gender Separated
The above applies to the communal (shared) baths. At facilities with private baths or private saunas, guests with tattoos may still be able to bathe. Please check with the facility for details.
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn moreA heartwarming chloride hot spring that springs up in peaceful satoyama
Nagano Saku City
"Fuse Onsen" is a day-use hot spring facility located in the peaceful countryside of Saku City, Nagano Prefecture. It features open-air baths with views of serene satoyama scenery right in front of you, as well as a spacious indoor bath, and has long been loved by locals. The water is colorless and clear, and is known as a sodium chloride hot spring that warms you thoroughly from the core and keeps you from cooling off easily. The sauna features a rotation system every week, with two types available: a blazing authentic dry sauna and a fragrant mist sauna that gently moisturizes the skin. It also pairs exceptionally well with the deep, mildly cool cold plunge bath and outdoor bathing while soaking up the satoyama breeze all over your body.
TypeNatural Hot Spring
This natural sodium chloride hot spring is highly praised for warming the body thoroughly, keeping you warm long after bathing, and making it hard to cool off afterward. Its mild weakly alkaline spring water is gentle on the skin, and in the open-air bath you can relax lavishly in a famous hot spring while enjoying the refreshing satoyama scenery that changes with the seasons.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity5people
A proper dry sauna with a comfortable old-fashioned atmosphere that makes the most of the warmth of wood. The temperature is kept high, and the strong, pleasant dry heat filling the room quickly warms you from the core and encourages refreshing sweating. The bathing areas for men and women switch every week.
Sauna TypeMist Sauna
Capacity6people
A gentle, easy-to-enter mist sauna where abundant warm steam spreads leisurely throughout the room. The high humidity makes it easy to breathe, and it softly moisturizes your skin, hair, and throat while warming you calmly and comfortably without putting strain on your body.
Water QualityTap Water
Capacity2people
A cold plunge bath installed right near the sauna room, featuring a distinctive deep design with no steps. The water temperature is set to be gentle on the body and not too cold, so even those who do not like the sudden shock of cold water can sink in comfortably and refresh their whole body pleasantly.
Closed Days: Open all year
384-2203 1228-1228 Fuse, Saku City, Nagano Prefecture
Gender Access
Gender Separated
The above applies to the communal (shared) baths. At facilities with private baths or private saunas, guests with tattoos may still be able to bathe. Please check with the facility for details.
Curated by an expert who visits onsen and sauna facilities every day and has explored 300+ locations — only facilities confirmed to be truly exceptional are featured.
Learn more