Ginzan Onsen — Taisho-Era Hot Spring Romance

Ginzan Onsen is 300 meters of Taisho-period (1912-1926) wooden ryokan squeezed into a mountain valley, three and four stories stacked on both banks of the Ginzan River. At dusk the gas lamps light—actual gas, not electric fakes—and if there's snow on the roofs (likely December through March), the scene goes full time-machine. The town was a silver camp until the Edo period (ginzan = silver mountain), then the mines played out and they pivoted to hot springs discovered while digging. Only 12 ryokan exist, plus Shirogane-yu public bath and one cafe. The whole town is walkable in 8 minutes if you don't stop to photograph. You will stop to photograph—this is the onsen town that inspired the bathhouse in Spirited Away, and it looks the part, especially once the day-trippers leave at 6pm and the gas lamps do their work. Overnight stays are the dream (you get the town to yourself after dark), but ryokan book 4-6 months out for winter weekends. Day visitors are tolerated; the town knows it's become an Instagram pilgrimage site and has adjusted.