Osaka Osaka City
Reach totonou to the limit with the signature ice bath and powerful bouna sauna
"Utopia Shiratama Onsen" is a sento in Osaka City, Osaka Prefecture. Its biggest highlights are the bouna sauna, where intense heat and steam rise from hidden heaters, and the signature ice bath, which regularly receives chunks of ice. After warming your body to the limit and then tightening it all at once in the deep cold plunge bath, you can enjoy blissful rest while feeling the pleasant breeze in the rooftop open-air relaxation area, which looks out over the chimney and the wide sky. There is also a wide range of baths, including a spacious high-carbonation spring bath, an open-air bath, and an esthetic bath, all of which help melt away everyday fatigue from deep within.

This clean and spacious large bath area offers a wide variety of tubs, including the main bath, a pleasantly stimulating esthetic bath, a medicinal bath, and an open-air bath where you can feel the outside air. You can refresh to your heart's content as you move from bath to bath according to your mood and condition that day.

A bouna sauna with heaters built into the space under the benches and elsewhere. During the periodically activated auto-löyly, a red lamp lights up and intense waves of heat and plenty of steam fill the room. More powerful heat than the thermometer suggests wraps around your whole body, and sweat pours out like a waterfall in a short time. You can also enjoy a self-made heat wave with the provided uchiwa fan, making this a scorching space where you can push yourself to the limit.

Waiting for a body heated to the limit by the sauna is the signature deep ice bath. Large blocks of ice are regularly dropped in from above with a rumbling sound, keeping the water at a sharply cold, refreshing temperature at all times. Sink your whole body in, and you will cool down instantly. After that, you can climb the stairs up to the rooftop and enjoy an exquisite outdoor air bath while gazing at the wide sky and the chimney.
Open Year-Round
Osaka
One of Japan's top saunas — Osaka's most powerful sauna
Osaka
A collection of world baths and Japan's largest 140-person sauna theater
Osaka
A lush premium spa featuring a natural hot spring drawn directly from the source and three types of sauna
JAPAN'S FINEST ONSEN & SAUNA
The Finest Onsen & Sauna in Japan
61 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.