Nagawa, Nagano

Obsidian flakes still surface in the soil around Hoshikuso Pass — a name that translates, roughly, as "star dung" — where Jomon-era people quarried the volcanic glass and carried it along trade routes that predate any road. Nagawa, formed when Nagato Town and Wada Village merged, sits on this layered ground: high-plateau farmland cut by the Yoda and Daimon rivers, with elevations that climb from valley floors toward the broad pastures of Utsukushigahara.

The Nakasendo once ran through here, and two post towns remain on the ground rather than in photographs. Wada-juku preserves its honjin and hatago structures from the Edo period, when this stretch of the highway was a tenryō — shogunate-administered territory. Nagakubo-juku, one station earlier along the road, bends at an unusual dog-leg angle, a layout that gives the town its particular street logic. Walking either one on a weekday, you notice the scale: narrow lots, deep eaves, the silence of a working agricultural town rather than a curated museum district.

Tachiiwa washi — handmade paper produced here — continues as a local craft, and enoki mushrooms come out of the surrounding farmland. At the Kokuyoseki Taiken Museum near the old quarry site, the obsidian itself is the exhibit: raw cores, worked blades, and the geological story of why this particular highland became a Jomon supply node. The material that traveled so far, so long ago, is still here.