A mixed-gender sauna garden and saunas in the men's and women's public baths. An ocean-view hot spring inn with a wide variety of sauna facilities
Hyogo Sumoto City
"Awaji International Hotel The Sunplaza" is a superb hot spring inn where every room offers a 180-degree panoramic view of the Kitan Strait. Guests can ease away everyday fatigue in the spacious public bath, open-air bath, waterfall bath, and bubble bath fed by the famous Sumoto Onsen. Another major attraction is its exceptionally well-equipped sauna facilities. On the grounds is a sauna garden to enjoy while wearing swimsuits, featuring a full-fledged "Nature Sauna" with low-temperature, high-humidity conditions that are gentle on the hair and skin, as well as a Finland-origin barrel-shaped "barrel sauna" available for private rental, where you can enjoy self-löyly. Right in front of the sauna is an outdoor cold bath equipped with a chiller, kept cold and temperature-controlled year-round. In addition, the main building's public bath area includes a high-temperature dry sauna for men and a Japanese-style kettle bath for women that gently provides moisture through a mist sauna, making this inn an outstanding choice for a sauna trip.
TypeNatural Hot Spring
You can enjoy Sumoto Onsen, known as the "Uruoi no Yu" or "Moisturizing Waters," in a variety of styles, including the spacious indoor bath of the large public bath, a scenic rock open-air bath with large stones, and waterfall and bubble baths. Its alkaline simple spring water is extremely gentle, helping with fatigue recovery, neuralgia, and sensitivity to cold while softly warming the body from deep within.
TypeNatural Hot Spring
Three luxurious private hot spring baths with different atmospheres: Shinonome, Sei-u, and Komorebi. In the relaxed, exclusive space that only a private bath can offer, you can enjoy Sumoto Onsen to yourself while admiring the superb ocean view through the large windows. It is ideal for private moments of relaxation with a loved one or your family.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity10people
A high-temperature dry sauna located inside the men's public bath on the first floor of the main building, in the sauna and spa center. This classic dry sauna is hot and dry, efficiently warming the body from the inside after you have already been warmed by the hot spring. In the relaxed atmosphere unique to a public bath, you can take your time and work up a satisfying sweat.
Sauna TypeMist Sauna
Capacity4people
A Japanese-style kettle bath mist sauna located inside the women's public bath on the first floor of the main building, in the sauna and spa center. Pleasant warm steam fills the room with gentle moisture, encouraging a mild sweat while hydrating the skin without placing excessive strain on the body. It is ideal for a leisurely, relaxing time.
Sauna TypeDry Sauna
Capacity15people
A full-fledged Finnish-style sauna located in the on-site sauna building, boasting one of the largest scales in the Kansai region. Its low-temperature, high-humidity setting is a key feature, allowing you to sweat comfortably while minimizing damage to your hair and skin. You can enjoy löyly by pouring aroma-infused water over the sauna stones and savoring the steam and fragrance. *As this is a mixed-gender area, swimsuits or sauna wear must be worn when using it.
Sauna TypeDry Sauna
Capacity4people
A Finland-origin barrel-shaped sauna that can be rented as a private single-building facility. The circular interior, surrounded by the scent of pine wood, offers excellent heat efficiency, allowing the room temperature to warm evenly. Without worrying about anyone else, you can pour water over the sauna stones at your own pace and enjoy superb self-löyly and the circulation of steam all to yourself.
Water Qualitytap
Capacity3people
An outdoor cold bath located right in front of the Nature Sauna and Barrel Sauna in the new sauna building. Because it uses a chiller, the water stays thoroughly cold and at the optimal temperature at all times, regardless of the season or outside temperature. It lets you cool down all at once after sauna bathing, and further enhances the synergy with outdoor air bathing while feeling the sea breeze.
Closed Days: None
〒656-0023 1279-13 Koji-dani, Sumoto City, Hyogo Prefecture, Awaji International Hotel The Sunplaza
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 moreA mixed-gender sauna garden and saunas in the men's and women's public baths. An ocean-view hot spring inn with a wide variety of sauna facilities
Hyogo Sumoto City
"Awaji International Hotel The Sunplaza" is a superb hot spring inn where every room offers a 180-degree panoramic view of the Kitan Strait. Guests can ease away everyday fatigue in the spacious public bath, open-air bath, waterfall bath, and bubble bath fed by the famous Sumoto Onsen. Another major attraction is its exceptionally well-equipped sauna facilities. On the grounds is a sauna garden to enjoy while wearing swimsuits, featuring a full-fledged "Nature Sauna" with low-temperature, high-humidity conditions that are gentle on the hair and skin, as well as a Finland-origin barrel-shaped "barrel sauna" available for private rental, where you can enjoy self-löyly. Right in front of the sauna is an outdoor cold bath equipped with a chiller, kept cold and temperature-controlled year-round. In addition, the main building's public bath area includes a high-temperature dry sauna for men and a Japanese-style kettle bath for women that gently provides moisture through a mist sauna, making this inn an outstanding choice for a sauna trip.
TypeNatural Hot Spring
You can enjoy Sumoto Onsen, known as the "Uruoi no Yu" or "Moisturizing Waters," in a variety of styles, including the spacious indoor bath of the large public bath, a scenic rock open-air bath with large stones, and waterfall and bubble baths. Its alkaline simple spring water is extremely gentle, helping with fatigue recovery, neuralgia, and sensitivity to cold while softly warming the body from deep within.
TypeNatural Hot Spring
Three luxurious private hot spring baths with different atmospheres: Shinonome, Sei-u, and Komorebi. In the relaxed, exclusive space that only a private bath can offer, you can enjoy Sumoto Onsen to yourself while admiring the superb ocean view through the large windows. It is ideal for private moments of relaxation with a loved one or your family.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity10people
A high-temperature dry sauna located inside the men's public bath on the first floor of the main building, in the sauna and spa center. This classic dry sauna is hot and dry, efficiently warming the body from the inside after you have already been warmed by the hot spring. In the relaxed atmosphere unique to a public bath, you can take your time and work up a satisfying sweat.
Sauna TypeMist Sauna
Capacity4people
A Japanese-style kettle bath mist sauna located inside the women's public bath on the first floor of the main building, in the sauna and spa center. Pleasant warm steam fills the room with gentle moisture, encouraging a mild sweat while hydrating the skin without placing excessive strain on the body. It is ideal for a leisurely, relaxing time.
Sauna TypeDry Sauna
Capacity15people
A full-fledged Finnish-style sauna located in the on-site sauna building, boasting one of the largest scales in the Kansai region. Its low-temperature, high-humidity setting is a key feature, allowing you to sweat comfortably while minimizing damage to your hair and skin. You can enjoy löyly by pouring aroma-infused water over the sauna stones and savoring the steam and fragrance. *As this is a mixed-gender area, swimsuits or sauna wear must be worn when using it.
Sauna TypeDry Sauna
Capacity4people
A Finland-origin barrel-shaped sauna that can be rented as a private single-building facility. The circular interior, surrounded by the scent of pine wood, offers excellent heat efficiency, allowing the room temperature to warm evenly. Without worrying about anyone else, you can pour water over the sauna stones at your own pace and enjoy superb self-löyly and the circulation of steam all to yourself.
Water Qualitytap
Capacity3people
An outdoor cold bath located right in front of the Nature Sauna and Barrel Sauna in the new sauna building. Because it uses a chiller, the water stays thoroughly cold and at the optimal temperature at all times, regardless of the season or outside temperature. It lets you cool down all at once after sauna bathing, and further enhances the synergy with outdoor air bathing while feeling the sea breeze.
Closed Days: None
〒656-0023 1279-13 Koji-dani, Sumoto City, Hyogo Prefecture, Awaji International Hotel The Sunplaza
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