Sawatari Hot Springs

The bus from Nakanojo Station follows the Agatsuma River into the mountains, and after about forty minutes the valley narrows and the road starts switching back up the hillside. Sawatari Hot Springs sits at the end of that climb, a small cluster of eleven ryokan beside a stream, with nothing much around it except forest and the sound of moving water. Most visitors to this corner of Gunma head straight for Kusatsu, which is forty minutes further up the road and far more famous. Sawatari is the quieter stop in between, and it has been serving bathers for over eight hundred years.

The water here is a calcium sulfate and sodium chloride type, and it differs noticeably from the aggressive acidic water at Kusatsu. At Sawatari, the bath is completely clear, without the milky turbidity you find at many sulfur springs, and the temperature is comfortable without any sharpness to it. There is a faint mineral character, something dry and clean at the back of the throat if you breathe deeply near the surface, but nothing that stings. The water feels neutral and steady on the skin, the kind of bath you can stay in for a long time without feeling overwhelmed. Historically, visitors would come to Kusatsu first for its strong, acidic waters, then stop at Sawatari on the way back to soothe skin irritated by the harsher spring.

That secondary role is part of what defines Sawatari. It has never chased the crowd that Kusatsu pulls, and the town shows it. The public bathhouse charges a few hundred yen and has two tubs, both heated from the same source. There are no souvenir shops worth mentioning, and the main street is quiet enough on a weekday that you might walk the full length of it without passing another person. The ryokan are mostly traditional and small, and several have wooden outdoor baths positioned above the stream.

The best reason to stop here is that combination of scale and water quality. You get a genuine mountain onsen without the coach-tour atmosphere that blankets Kusatsu on weekends. In late October, the maple and beech trees along the Agatsuma valley turn color, and if you catch that timing, the hillside above the inn rooftops looks like it is on fire. The water is calm, the surroundings are dramatic, and the whole place costs a fraction of what a night at a big Kusatsu ryokan will set you back.