An urban oasis where you can unwind in jet-black black water rising from 1200 m underground and an ocher sauna
Tokyo Setagaya City
"THE SPA Seijo" is a natural hot spring facility in Setagaya City, Tokyo. Its bicarbonate spring water, which rises from deep underground, is known for its beautiful black water, a gift from ancient times, and is widely praised as a skin-beautifying bath that leaves the skin smooth. The open-air area also features pot baths with free-flowing spring water. The sauna is an ocher sauna, with walls made using ocher, where the powerful heat of far-infrared rays and a comfortable level of humidity encourage pleasant sweating. The spacious, deep cold plunge bath quickly cools down your heated body after the sauna. Forget the bustle of the city and refresh both body and mind with the high-quality black water and sauna.
TypeNatural Hot Spring
A natural black water hot spring rich in minerals, rising from 1200 m underground. Its mildly alkaline, soft texture is expected to provide excellent heat retention and moisturizing benefits. You can enjoy this jet-black water in both the indoor baths and the open-air baths.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity20people
A calm dry sauna with ocher used on the walls. The powerful heat from far-infrared rays warms the body to the core, while ingredients released from the ocher help support a pleasant sweat. The spacious three-tiered room lets you relax and face yourself at your own pace.
Sauna TypeMist Sauna
A steam mist sauna for women only. Wrapped in the scent of hinoki cypress, even those who do not like high-temperature saunas can refresh comfortably. The moist steam hydrates the skin and gently warms the body.
Sauna TypeSalt Sauna
A salt sauna for women only. You can experience the sweat-inducing effect of the sauna and the skin-beautifying benefits of salt at the same time. It helps promote the elimination of excess subcutaneous fat and improves skin firmness. You may also bring your own salt to use.
Water QualityTap Water
Capacity8people
A spacious, deep cold plunge bath located right next to the sauna. Its strong chill quickly tightens up your heated body. It has a large capacity, so you can enjoy a leisurely cool-down.
Closed Days: None
2F, Central Wellness Town, 3-20-2 Chitosedai, Setagaya City, Tokyo 157-0071, 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 urban oasis where you can unwind in jet-black black water rising from 1200 m underground and an ocher sauna
Tokyo Setagaya City
"THE SPA Seijo" is a natural hot spring facility in Setagaya City, Tokyo. Its bicarbonate spring water, which rises from deep underground, is known for its beautiful black water, a gift from ancient times, and is widely praised as a skin-beautifying bath that leaves the skin smooth. The open-air area also features pot baths with free-flowing spring water. The sauna is an ocher sauna, with walls made using ocher, where the powerful heat of far-infrared rays and a comfortable level of humidity encourage pleasant sweating. The spacious, deep cold plunge bath quickly cools down your heated body after the sauna. Forget the bustle of the city and refresh both body and mind with the high-quality black water and sauna.
TypeNatural Hot Spring
A natural black water hot spring rich in minerals, rising from 1200 m underground. Its mildly alkaline, soft texture is expected to provide excellent heat retention and moisturizing benefits. You can enjoy this jet-black water in both the indoor baths and the open-air baths.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity20people
A calm dry sauna with ocher used on the walls. The powerful heat from far-infrared rays warms the body to the core, while ingredients released from the ocher help support a pleasant sweat. The spacious three-tiered room lets you relax and face yourself at your own pace.
Sauna TypeMist Sauna
A steam mist sauna for women only. Wrapped in the scent of hinoki cypress, even those who do not like high-temperature saunas can refresh comfortably. The moist steam hydrates the skin and gently warms the body.
Sauna TypeSalt Sauna
A salt sauna for women only. You can experience the sweat-inducing effect of the sauna and the skin-beautifying benefits of salt at the same time. It helps promote the elimination of excess subcutaneous fat and improves skin firmness. You may also bring your own salt to use.
Water QualityTap Water
Capacity8people
A spacious, deep cold plunge bath located right next to the sauna. Its strong chill quickly tightens up your heated body. It has a large capacity, so you can enjoy a leisurely cool-down.
Closed Days: None
2F, Central Wellness Town, 3-20-2 Chitosedai, Setagaya City, Tokyo 157-0071, 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