Completely free-flowing source spring! Supreme hot spring and sauna that merge with Saito's sky
Miyazaki Saito City
Located at the foot of the Saitobaru Kofun Cluster, Tsumayu is a day-use hot spring facility that prides itself on completely free-flowing water from the source with no reheating or added water. The colorless, transparent sodium bicarbonate hot spring yields 300 L per minute, is gentle on the skin, and is also drinkable. Sauna enthusiasts will love it: a spacious hinoki cypress–scented sauna room reaches over 90°C on the top bench, providing an intense heat. After the sauna you can take a plunge into the huge groundwater-fed cold plunge bath that can hold around 15 people. Enjoy open-air relaxation while gazing at the beautiful garden and Saito's wide sky, plus floatation bathing in the 30°C low-temperature bath—everything here offers extraordinary scale and restorative comfort.
TypeNatural Hot Spring
A sodium bicarbonate (bicarbonate) hot spring (weakly alkaline) gushing from a depth of 1483 m. The spring temperature is 46.1°C, and the water is delivered as a completely free-flowing source with no reheating or added water. Enjoy vast indoor baths, an open rock bath that connects seamlessly to the garden, and semi-open baths that let you feel the breeze—large-scale bathing facilities where you can savor this ancient water.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity30people
A large far-infrared dry sauna that comfortably accommodates 20–30 people with a pleasant hinoki cypress aroma. It has three-tiered benches, and the top bench is set at a robust high temperature exceeding 90°C. Thoughtful touches include two types of dedicated sauna mats: one for feet and one for sitting.
Water QualityNatural Water (Groundwater, Spring, etc.)
Capacity15people
Located immediately outside the sauna, this oversized cold plunge bath easily fits 10–15 people. It uses groundwater and stays at a mild temperature around 20°C, making it approachable even for those new to cold plunges and allowing a slow, extended cool-down after a high-temperature sauna.
Water Qualitynatural
Capacity10people
An approximately 30°C low-temperature hot spring in the open-air area. After the cold plunge, alternating between the cold plunge and this cool bath—or floating while resting to achieve totonou—is highly praised by sauna enthusiasts and is a hidden specialty of the facility.
Closed Days: Tuesday
687-5 Shodono, Saito, Miyazaki 881-0023, 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
Completely free-flowing source spring! Supreme hot spring and sauna that merge with Saito's sky
Miyazaki Saito City
Located at the foot of the Saitobaru Kofun Cluster, Tsumayu is a day-use hot spring facility that prides itself on completely free-flowing water from the source with no reheating or added water. The colorless, transparent sodium bicarbonate hot spring yields 300 L per minute, is gentle on the skin, and is also drinkable. Sauna enthusiasts will love it: a spacious hinoki cypress–scented sauna room reaches over 90°C on the top bench, providing an intense heat. After the sauna you can take a plunge into the huge groundwater-fed cold plunge bath that can hold around 15 people. Enjoy open-air relaxation while gazing at the beautiful garden and Saito's wide sky, plus floatation bathing in the 30°C low-temperature bath—everything here offers extraordinary scale and restorative comfort.
TypeNatural Hot Spring
A sodium bicarbonate (bicarbonate) hot spring (weakly alkaline) gushing from a depth of 1483 m. The spring temperature is 46.1°C, and the water is delivered as a completely free-flowing source with no reheating or added water. Enjoy vast indoor baths, an open rock bath that connects seamlessly to the garden, and semi-open baths that let you feel the breeze—large-scale bathing facilities where you can savor this ancient water.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity30people
A large far-infrared dry sauna that comfortably accommodates 20–30 people with a pleasant hinoki cypress aroma. It has three-tiered benches, and the top bench is set at a robust high temperature exceeding 90°C. Thoughtful touches include two types of dedicated sauna mats: one for feet and one for sitting.
Water QualityNatural Water (Groundwater, Spring, etc.)
Capacity15people
Located immediately outside the sauna, this oversized cold plunge bath easily fits 10–15 people. It uses groundwater and stays at a mild temperature around 20°C, making it approachable even for those new to cold plunges and allowing a slow, extended cool-down after a high-temperature sauna.
Water Qualitynatural
Capacity10people
An approximately 30°C low-temperature hot spring in the open-air area. After the cold plunge, alternating between the cold plunge and this cool bath—or floating while resting to achieve totonou—is highly praised by sauna enthusiasts and is a hidden specialty of the facility.
Closed Days: Tuesday
687-5 Shodono, Saito, Miyazaki 881-0023, 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