Scenic open-air bath and indoor bath
TypeNatural Hot Spring
A scenic natural hot spring with panoramic views of Mount Asama from the fifth floor.
Spectacular open-air relaxation overlooking Mount Asama and a mist sauna
Nagano Saku City
Nozomi Sunpia Saku in Saku City is a facility renowned for its scenic natural hot spring on the fifth floor. In addition to a dry sauna, it offers a moisturizing mist sauna. The outdoor area features a long-awaited single-person cold plunge bath (continuously flowing tap water) and a totonou space equipped with infinity chairs. After your soak, you can enjoy the ultimate open-air relaxation while taking in panoramic views of Mount Asama and the Saku Plain.
TypeNatural Hot Spring
A scenic natural hot spring with panoramic views of Mount Asama from the fifth floor.
Sauna TypeDry Sauna
Stove Typeelectric_far_infrared
Capacity6people
A compact dry sauna. Its mild temperature setting lets you work up a steady sweat.
Sauna TypeSteam Sauna
Capacity7people
A mist sauna where pleasantly warm steam showers you. It is reputed to promote more sweating than the dry sauna.
Water QualityTap Water
Capacity1people
A newly installed single-person ceramic cold plunge bath in the outdoor area. It becomes ice-cold in winter.
Closed Days: None
3203-2 Negishi, Saku, Nagano 385-0062, 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
Spectacular open-air relaxation overlooking Mount Asama and a mist sauna
Nagano Saku City
Nozomi Sunpia Saku in Saku City is a facility renowned for its scenic natural hot spring on the fifth floor. In addition to a dry sauna, it offers a moisturizing mist sauna. The outdoor area features a long-awaited single-person cold plunge bath (continuously flowing tap water) and a totonou space equipped with infinity chairs. After your soak, you can enjoy the ultimate open-air relaxation while taking in panoramic views of Mount Asama and the Saku Plain.
TypeNatural Hot Spring
A scenic natural hot spring with panoramic views of Mount Asama from the fifth floor.
Sauna TypeDry Sauna
Stove Typeelectric_far_infrared
Capacity6people
A compact dry sauna. Its mild temperature setting lets you work up a steady sweat.
Sauna TypeSteam Sauna
Capacity7people
A mist sauna where pleasantly warm steam showers you. It is reputed to promote more sweating than the dry sauna.
Water QualityTap Water
Capacity1people
A newly installed single-person ceramic cold plunge bath in the outdoor area. It becomes ice-cold in winter.
Closed Days: None
3203-2 Negishi, Saku, Nagano 385-0062, 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