Enjoy one of the Kanto region's most concentrated beautifying baths with fully free-flowing source water
Saitama Kuki City
"Hyakukannon Onsen" is a natural hot spring facility in Kuki City, Saitama Prefecture, known for its impressive abundance of water and rich mineral content. It offers a luxurious 57°C source spring that wells up from 1,200 m underground as a fully free-flowing spring with no added water or heating. The sodium chloride strong saline spring known as the "beautifying bath" is rich in metaboric acid and is said to be especially effective for disinfection and skin beautification. The saunas are fully equipped in both the "Bosatsu no Yu" and "Amida no Yu" areas, which alternate between men and women every two weeks, allowing you to work up a good sweat in a freshly renovated, spotless space. With a cold plunge bath fed by natural groundwater, a high-concentration carbonated spring using the source water, and various baths including a "hot bath" over 45°C, this is a famous hot spring spot with a wide variety of baths that even onsen enthusiasts will appreciate.
TypeNatural Hot Spring
An open-air stone bath offering a rich 57°C naturally gushing source spring in a fully free-flowing state with no added water or heating. The sodium chloride strong saline spring’s minerals soak into the body, help prevent you from cooling down after bathing, and leave your skin smooth. This is the main bath of Hyakukannon Onsen.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity10people
A dry sauna renovated in 2025, with the pleasant scent of new wood. Stable heat of around 90°C fills the room, encouraging deep, steady sweating. A clean and refreshing space that can be enjoyed under the men-women alternating system every two weeks.
Water QualityNatural Water (Groundwater, Spring, etc.)
Capacity4people
A gently textured cold plunge bath fed by groundwater and free-flowing from the source. It instantly tightens the heat from your body after the sauna and promises a refreshing cooldown.
Water Qualitywell
Capacity4people
A cold plunge bath on the Bosatsu no Yu side, characterized by its slightly warmer water temperature of around 22°C. With the mellow feel unique to groundwater, even those who are not fond of cold plunge baths can cool down comfortably and thoroughly.
Closed Days: None
340-0206 2-19-1 Nishiowari, Kuki City, Saitama Prefecture
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
Enjoy one of the Kanto region's most concentrated beautifying baths with fully free-flowing source water
Saitama Kuki City
"Hyakukannon Onsen" is a natural hot spring facility in Kuki City, Saitama Prefecture, known for its impressive abundance of water and rich mineral content. It offers a luxurious 57°C source spring that wells up from 1,200 m underground as a fully free-flowing spring with no added water or heating. The sodium chloride strong saline spring known as the "beautifying bath" is rich in metaboric acid and is said to be especially effective for disinfection and skin beautification. The saunas are fully equipped in both the "Bosatsu no Yu" and "Amida no Yu" areas, which alternate between men and women every two weeks, allowing you to work up a good sweat in a freshly renovated, spotless space. With a cold plunge bath fed by natural groundwater, a high-concentration carbonated spring using the source water, and various baths including a "hot bath" over 45°C, this is a famous hot spring spot with a wide variety of baths that even onsen enthusiasts will appreciate.
TypeNatural Hot Spring
An open-air stone bath offering a rich 57°C naturally gushing source spring in a fully free-flowing state with no added water or heating. The sodium chloride strong saline spring’s minerals soak into the body, help prevent you from cooling down after bathing, and leave your skin smooth. This is the main bath of Hyakukannon Onsen.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity10people
A dry sauna renovated in 2025, with the pleasant scent of new wood. Stable heat of around 90°C fills the room, encouraging deep, steady sweating. A clean and refreshing space that can be enjoyed under the men-women alternating system every two weeks.
Water QualityNatural Water (Groundwater, Spring, etc.)
Capacity4people
A gently textured cold plunge bath fed by groundwater and free-flowing from the source. It instantly tightens the heat from your body after the sauna and promises a refreshing cooldown.
Water Qualitywell
Capacity4people
A cold plunge bath on the Bosatsu no Yu side, characterized by its slightly warmer water temperature of around 22°C. With the mellow feel unique to groundwater, even those who are not fond of cold plunge baths can cool down comfortably and thoroughly.
Closed Days: None
340-0206 2-19-1 Nishiowari, Kuki City, Saitama Prefecture
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