[Access] About 20 minutes by bus from JR Kurayoshi Station (San-in Main Line) bound for Misasa Onsen
[Rakuten Travel HP] Misasa Onsen Ryokan Ohashi

Misasa Onsen’s Ryokan Ohashi. This historic inn is a Registered Tangible Cultural Property, featuring a grand building constructed with plenty of fine wood and guest rooms where no two are alike.

At Ryokan Ohashi, you can enjoy four different types of baths: the open-air bath, “Gankutsu no Yu” (Cave Bath), “Fukube no Yu,” and private baths. The photo on the left is the view from the open-air bath—the way the orange lamps on the opposite bank glowed as the sky gradually turned from blue to black at twilight was just stunning. Gankutsu no Yu features the “Upper Bath,” which contains thorium (said to be rare even worldwide), and the “Middle” and “Lower” baths, which are radium springs that bubble up directly from the rocky floor. Just watching the water welling up abundantly is so relaxing. The indoor “Fukube no Yu” also has a lie-down bath (neyu).
Apparently, the process of activating the body through low-level radiation is called the “hormesis effect.” To effectively achieve this by inhaling steam from the radioactive spring, a sauna is provided in the open-air bath area. The spring quality is a weak radioactive sodium-chloride spring. It was the same when I visited Masutomi Radium Onsen, but radioactive springs really seem to leave me feeling sluggish after a soak—though that heaviness makes for a great nap, which feels amazing (lol)!