Kai Hakone is one of Hoshino Resorts’ renovated ryokans, perched above the wooded ravine of Hakone Yumoto Onsen on what was once the Old Tokaido Road — the Edo-period highway between Tokyo and Kyoto. The 34 rooms are designed around the historical rhythm of weary travellers stopping there to recover; many suites carry their own private hot spring baths, and the property includes a new outdoor tea house (Sawa Chaya), a marquetry workshop (Hakone is the home of yosegi-zaiku inlay), and kaiseki dinners that quote the period directly. The kind of stay that gives you a reason to take the slow train in.