Saitama Soka City
Located in Soka City, Saitama Prefecture, the Yunoizumi Soka Health Center is a prestigious bathing facility that has been leading sauna culture. The high-temperature sauna, with a three-tier structure accommodating up to 40 people, hosts heat wave löyly sessions where you can experience a heat sensation exceeding 100°C, promoting heavy sweating and a refreshing heat experience. The cold plunge bath uses continuously flowing underground water, enveloping the body in a soft, clear coldness. Outdoors, there is an artificial hot spring called 'Kusatsu no Yu,' replicating the beneficial components of Kusatsu Onsen, with the scent of sulfur and the stimulating water providing a pleasant and healing experience. The facility also offers dining and relaxation spaces, allowing you to enjoy a 'cycle of heat and healing' throughout the day.
An artificial hot spring replicating the authentic Kusatsu no Yu, using a liquid bath additive concentrated with the beneficial components of Kusatsu Onsen in Gunma Prefecture. It features a sulfur scent similar to acidic waters, tightening the skin and promoting blood circulation. After bathing, the warmth lingers, allowing you to easily enjoy the refreshing sensation unique to Kusatsu.
A standard high-temperature sauna with a three-tier structure that can accommodate up to 40 people, featuring a high ceiling. Equipped with two gas and stone heaters, it maintains high temperature and humidity. During scheduled löyly events, steam and heat rise rapidly, designed to promote sweating and provide a strong heat impact.
Known as the 'Strong Vibra Cold Plunge Bath that Strips Away the Protective Layer,' it uses abundant underground water in a continuous flow. Although the set temperature is about 15°C, the vibra and clear water quality make the perceived temperature even lower. It is the perfect cold plunge bath for cooling down right after a sauna.
Irregular Holidays
Visited by the Editor-in-Chief
The Editor-in-Chief visited in person in December 2025
Shocked by the Queue for the Sauna
Read the full review
Saitama
A bathing resort with natural hot springs, three types of saunas, and three types of cold plunge baths
Saitama
Be soothed by a large public bath and sauna that feel like a forest spring in the bonsai city of Omiya
Saitama
JAPAN'S FINEST ONSEN & SAUNA
The Finest Onsen & Sauna in Japan
57 SELECTIONS
Most of what we surveyed never even made it onto this site. This book is a further cut from what did. Our editor bathed in every onsen and sauna in it, and wrote only what they confirmed on the ground.
