A sodium bicarbonate beauty bath and luxurious relaxation with hot spring water used in all faucets
Saitama Fukaya City
"Kokusaiji Natural Hot Spring Bijin-no-Yu" is a day-use hot spring facility in Fukaya City, Saitama Prefecture. The source water, gushing up from about 1,134 m underground, is rich in sodium bicarbonate, which helps remove old dead skin cells, and metasilicic acid, which supports moisture retention, and as its name suggests, it is beloved as a "beauty bath." Its biggest feature is the luxurious setup of using natural hot spring water for all showers and faucets except the cold plunge bath. The sauna includes a powerful far-infrared sauna for men, a Rocky sauna for women, and a salt sauna that helps care for the skin. Together with outdoor air bathing in the open-air bath area, you can fully enjoy Fukaya's abundant hot spring water with your whole body.
TypeNatural Hot Spring
A simple hot spring gushing from 1,134 m underground, rich in sodium bicarbonate and metasilicic acid. It is known as a "beauty bath" that softens the skin's dead layer and enhances moisturizing effects. In addition to the open-air bath and large public bath, this source water is also used lavishly in the showers and faucets.
Sauna TypeSalt Sauna
Capacity12people
A steam-style salt sauna wrapped in plenty of vapor. By bathing while applying the provided salt all over your body, you can open your pores and enjoy a detox effect that helps leave your skin smooth. The synergy with the hot spring minerals offers an even greater beauty-skin experience.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity18people
A dry sauna installed in the men's bath, characterized by its powerful heat. With a high-temperature setting of around 90°C to 96°C, it warms the body efficiently from within through far-infrared effects and promotes heavy sweating. The spacious interior creates an open atmosphere where you can slowly work up a sweat while watching TV.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity20people
A Rocky sauna installed in the women's bath, with sauna stones stacked inside. While the temperature setting is mild, the moderate humidity allows for comfortable sweating. With less strain on the body, it is a popular space for women who want to refresh themselves slowly and thoroughly.
Water QualityTap Water
Capacity8people
A spacious cold plunge bath that gently cools down and tightens your body after sauna use. The water temperature is set to be relatively easy to enter, so both sauna beginners and experienced users can enjoy it. Fresh, clean water is constantly maintained, leading you into a refreshing cool-down.
Closed Days: None
〒366-0033 510-1 Kokusaiji, Fukaya 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
A sodium bicarbonate beauty bath and luxurious relaxation with hot spring water used in all faucets
Saitama Fukaya City
"Kokusaiji Natural Hot Spring Bijin-no-Yu" is a day-use hot spring facility in Fukaya City, Saitama Prefecture. The source water, gushing up from about 1,134 m underground, is rich in sodium bicarbonate, which helps remove old dead skin cells, and metasilicic acid, which supports moisture retention, and as its name suggests, it is beloved as a "beauty bath." Its biggest feature is the luxurious setup of using natural hot spring water for all showers and faucets except the cold plunge bath. The sauna includes a powerful far-infrared sauna for men, a Rocky sauna for women, and a salt sauna that helps care for the skin. Together with outdoor air bathing in the open-air bath area, you can fully enjoy Fukaya's abundant hot spring water with your whole body.
TypeNatural Hot Spring
A simple hot spring gushing from 1,134 m underground, rich in sodium bicarbonate and metasilicic acid. It is known as a "beauty bath" that softens the skin's dead layer and enhances moisturizing effects. In addition to the open-air bath and large public bath, this source water is also used lavishly in the showers and faucets.
Sauna TypeSalt Sauna
Capacity12people
A steam-style salt sauna wrapped in plenty of vapor. By bathing while applying the provided salt all over your body, you can open your pores and enjoy a detox effect that helps leave your skin smooth. The synergy with the hot spring minerals offers an even greater beauty-skin experience.
Sauna TypeDry Sauna
Stove TypeInfrared Heater
Capacity18people
A dry sauna installed in the men's bath, characterized by its powerful heat. With a high-temperature setting of around 90°C to 96°C, it warms the body efficiently from within through far-infrared effects and promotes heavy sweating. The spacious interior creates an open atmosphere where you can slowly work up a sweat while watching TV.
Sauna TypeDry Sauna
Stove TypeConvection Stove (Sauna Stone)
Capacity20people
A Rocky sauna installed in the women's bath, with sauna stones stacked inside. While the temperature setting is mild, the moderate humidity allows for comfortable sweating. With less strain on the body, it is a popular space for women who want to refresh themselves slowly and thoroughly.
Water QualityTap Water
Capacity8people
A spacious cold plunge bath that gently cools down and tightens your body after sauna use. The water temperature is set to be relatively easy to enter, so both sauna beginners and experienced users can enjoy it. Fresh, clean water is constantly maintained, leading you into a refreshing cool-down.
Closed Days: None
〒366-0033 510-1 Kokusaiji, Fukaya 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