The road from Numata takes the better part of an hour and a half by bus, climbing steadily into the mountains of Gunma along the upper reaches of the Katashina River. By the time you arrive, the valley has narrowed, and Hotaka-yama rises to the west with a quiet authority. Katashina Onsen sits on the mountain's eastern flank — a small accumulation of inns and baths that has, in its way, been here a long time. The waters were once known as Yuzawa Yakushi, a name that carries the faint trace of medicinal faith, and in 1983 the area was formally designated a national health resort. That designation matters less than what it implies: people have come here not for spectacle, but for restoration.

The waters themselves are sodium bicarbonate and alkaline simple springs, rising from the earth at temperatures between thirty-nine and fifty-three degrees. They are the kind of waters that ask something of you — not drama, but patience. To stay several nights is to begin to feel the rhythm of the place: mornings that belong to the bath, afternoons that open slowly toward the surrounding hills.

What makes Katashina unusual is the particular coexistence it has arrived at. Ski slopes sit nearby — Iwakura, Katashina Kogen — and yet the older character of the settlement, the quality of a working mountain cure, has not entirely dissolved into leisure. The two exist in a kind of honest tension. The place does not resolve itself neatly, and that, perhaps, is what keeps it from feeling constructed.