Tocen Goshoboh is truly like taking a step back in time.
It is a traditional Japanese ryokan (inn) that is one of the oldest ryokan in Japan, having been founded in 1191. The inn is named "Goshoboh" (御所坊), which means "Imperial Palace Inn," after a visit by the shogun Ashikaga Yoshimitsu in the 14th century.
Located in a quiet area of Arima Onsen, surrounded by mountains and forests.
And it has one of the coolest open-air onsens - as is always the case, men and women bathe separately, but the open-air onsen is a single space divided by a lower wall. Thanks to the special water color, it is not transparent, but still be sure to submerge your entire body in the water if you are in the section of the onsen with the lower part of the wall.