An authentic sauna in Seiyo City with the scent of 300-year-old cedar and an ultra-cold soy sauce barrel cold plunge bath
Ehime Seiyo City
Uwa Sauna is an authentic, male-only sauna facility that opened on February 1, 2026 inside Uwa Park Hotel in Seiyo City, Ehime. The sauna room is built with locally grown cedar approximately 300 years old, and offers a quiet, TV-free environment where guests can enjoy self-löyly. The cold plunge baths reuse barrels from the local soy sauce maker Yamami Shoyu and are chilled by a chiller to around 15°C, providing an exceptional cold plunge experience. The facility is packed with features that will delight sauna enthusiasts, including alternating high-temperature and neutral-temperature bathing, and a fully flat indoor reclining rest area.
TypeArtificial Hot Spring
While not a natural hot spring, the facility provides bathing options designed to maximize the sauna experience. Guests can warm up thoroughly in the approximately 42°C high-temperature bath or sink into the approximately 36°C neutral-temperature bath after sauna and cold plunge sessions to achieve deep relaxation, enabling a variety of bathing routines.
Sauna TypeDry Sauna
Stove Typeelectric
The sauna room is wrapped in the aroma of cedar aged about 300 years, harvested from the hillside behind Yamada Yakushi. There are two tiers of seating on each side of the stove and the room can accommodate around 14 people. With no TV, guests can face themselves in silence. A unique self-löyly practice is available where guests pour original aroma water using a yubi shoyu sashi, letting soft heat and fragrant steam slowly descend for a sublime relaxation experience.
Water Qualitytap
Two side-by-side cold plunge baths are made from reused soy sauce barrels formerly used by local Yamami Shoyu, each deeper than 110 cm. One is equipped with a chiller and is chilled to around 15°C (in winter it can sometimes drop to single digits), offering an intensely cold plunge. The other is at ambient temperature. Adjacent to these are a roughly 36°C neutral-temperature bath and a roughly 42°C high-temperature bath, allowing guests to enjoy cold-cold alternating bathing or warm-cold alternating bathing according to preference. Resting takes place on a fully flat reclining seat inside the bathing area.
Closed Days: None
330 Kamimatsuba, Uwa-cho, Seiyo City, Ehime 797-0046, 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
An authentic sauna in Seiyo City with the scent of 300-year-old cedar and an ultra-cold soy sauce barrel cold plunge bath
Ehime Seiyo City
Uwa Sauna is an authentic, male-only sauna facility that opened on February 1, 2026 inside Uwa Park Hotel in Seiyo City, Ehime. The sauna room is built with locally grown cedar approximately 300 years old, and offers a quiet, TV-free environment where guests can enjoy self-löyly. The cold plunge baths reuse barrels from the local soy sauce maker Yamami Shoyu and are chilled by a chiller to around 15°C, providing an exceptional cold plunge experience. The facility is packed with features that will delight sauna enthusiasts, including alternating high-temperature and neutral-temperature bathing, and a fully flat indoor reclining rest area.
TypeArtificial Hot Spring
While not a natural hot spring, the facility provides bathing options designed to maximize the sauna experience. Guests can warm up thoroughly in the approximately 42°C high-temperature bath or sink into the approximately 36°C neutral-temperature bath after sauna and cold plunge sessions to achieve deep relaxation, enabling a variety of bathing routines.
Sauna TypeDry Sauna
Stove Typeelectric
The sauna room is wrapped in the aroma of cedar aged about 300 years, harvested from the hillside behind Yamada Yakushi. There are two tiers of seating on each side of the stove and the room can accommodate around 14 people. With no TV, guests can face themselves in silence. A unique self-löyly practice is available where guests pour original aroma water using a yubi shoyu sashi, letting soft heat and fragrant steam slowly descend for a sublime relaxation experience.
Water Qualitytap
Two side-by-side cold plunge baths are made from reused soy sauce barrels formerly used by local Yamami Shoyu, each deeper than 110 cm. One is equipped with a chiller and is chilled to around 15°C (in winter it can sometimes drop to single digits), offering an intensely cold plunge. The other is at ambient temperature. Adjacent to these are a roughly 36°C neutral-temperature bath and a roughly 42°C high-temperature bath, allowing guests to enjoy cold-cold alternating bathing or warm-cold alternating bathing according to preference. Resting takes place on a fully flat reclining seat inside the bathing area.
Closed Days: None
330 Kamimatsuba, Uwa-cho, Seiyo City, Ehime 797-0046, 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