This is the hottest bath I have experienced in my 15 plus years in Japan. The first bath is the so-so hot bath at 44 ˚C, the other bath doesn't say how hot it is. I like hot baths but this one was painful. I was able to get in and sit down in it for 30 seconds or so and I am proud of that. Somewhere in between this bath and the 44 ˚C one is my sweet hot bath spot. Outdoor is a cooler 39˚C or 40˚C bath to relax in. Sadly, no cold water. That would have been awesome. It is a simple bath house so unless you are really into feeling the natural heat of the water here, I might skip this one. Like the other Shimosuwa baths, the water is clear, and you can really feel the effect after you dry off. The hot bath today was 47.3 ˚C. They cool off the baths by mixing the cooler 30 ˚C well water with the hotter 56 ˚C well.
Amazing place if you are in the mood for a boil!
Of the 3 bathhouses on the route this one is the newest and hottest. The outdoor bath, however, is the coolest option among all the baths available at all 3 locations.