Yunoya Hotel 湯の家旅館

Yunoya sits on the shore of Lake Yu in Nikko Yumoto, an old and plainly run ryokan rather than a polished resort. There's no open-air bath, just a single large indoor bath, but it holds proper sulfur water: milky and faintly emerald-tinged, with a mild sulfur smell. Overnight guests can also slip into a small private bath free of charge whenever it's open, no booking required. The building wears its age openly, with weathered walls and an entrance that can take a minute to find, and more than one visitor has come back thanks to the proprietress's genuine, apologetic care when something (a tap, the heating) isn't quite working that day. People return here for the water and the welcome, not the finish.