Famed Yakuoji spring water, herbal medicinal bath, steam sauna and cold plunge bath
Fukuoka Koga City
Kairakusou, a bathing facility in the Yakuoji area of Koga, is known for its signature medicinal bath made by steeping Chinese herbal ingredients in famed water that contains radon and metaboric acid. You can enjoy this traditional medicinal-bath culture, which has been featured on TV and in magazines, in a modern super sento style. The gender-separated bathing areas include a steam sauna and a cold plunge bath using natural spring water; many recommend their own way to totonou (state of perfect relaxation): warm the body in the medicinal bath, sweat in the sauna, and finish in the cold plunge. There is also a large hall, nap rooms, and a dining area, and some guests stay from morning baths through the evening. Easily accessible by car from Fukuoka City, it is a well-known medicinal-bath sauna destination toward the Kitakyushu area.
TypeSpecialty Bath
In addition to a medicinal bath blended with eight types of herbal medicinal ingredients using the famed spring water, multiple bathing pools are provided including jets, an open-air bath, and plain hot water baths. Special event baths and seasonal herbal herb baths are also sometimes offered.
Sauna TypeSteam Sauna
Stove Typeelectric
Capacity6people
A Bona sauna-style steam unit. Steam rises at regular intervals, and the humidity is designed to help the steam's components adhere to a body already warmed by the medicinal bath.
Water QualityNatural Water (Groundwater, Spring, etc.)
Capacity3people
A cold plunge bath using Yakuoji's natural spring water. Its mild water quality is used for cooling down after a sauna and to help reinforce the effects of the medicinal bath.
Closed Days: Wednesday
381 Yakuoji, Koga, Fukuoka 811-3124, Japan
Gender Access
Gender Separated
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
Famed Yakuoji spring water, herbal medicinal bath, steam sauna and cold plunge bath
Fukuoka Koga City
Kairakusou, a bathing facility in the Yakuoji area of Koga, is known for its signature medicinal bath made by steeping Chinese herbal ingredients in famed water that contains radon and metaboric acid. You can enjoy this traditional medicinal-bath culture, which has been featured on TV and in magazines, in a modern super sento style. The gender-separated bathing areas include a steam sauna and a cold plunge bath using natural spring water; many recommend their own way to totonou (state of perfect relaxation): warm the body in the medicinal bath, sweat in the sauna, and finish in the cold plunge. There is also a large hall, nap rooms, and a dining area, and some guests stay from morning baths through the evening. Easily accessible by car from Fukuoka City, it is a well-known medicinal-bath sauna destination toward the Kitakyushu area.
TypeSpecialty Bath
In addition to a medicinal bath blended with eight types of herbal medicinal ingredients using the famed spring water, multiple bathing pools are provided including jets, an open-air bath, and plain hot water baths. Special event baths and seasonal herbal herb baths are also sometimes offered.
Sauna TypeSteam Sauna
Stove Typeelectric
Capacity6people
A Bona sauna-style steam unit. Steam rises at regular intervals, and the humidity is designed to help the steam's components adhere to a body already warmed by the medicinal bath.
Water QualityNatural Water (Groundwater, Spring, etc.)
Capacity3people
A cold plunge bath using Yakuoji's natural spring water. Its mild water quality is used for cooling down after a sauna and to help reinforce the effects of the medicinal bath.
Closed Days: Wednesday
381 Yakuoji, Koga, Fukuoka 811-3124, Japan
Gender Access
Gender Separated
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