Nishiyama Onsen Keiunkan

Guinness's 'world's oldest hotel', freshly renovated: unheated, undiluted free-flowing water from every bath and tap, 24-hour baths and a seafood-free mountain kaiseki — at the end of a long road lined with dump trucks

Keiunkan dates its spring to 705, and in 2011 Guinness recognised it as the world's oldest hotel. Don't expect an ancient wooden building, though: the inn was rebuilt in 1997 as a four-storey concrete ryokan with wood interiors, the old operating company was dissolved in 2018 and the business moved to a new company, and it closed from November 2025 to March 2026 for a renovation that redid the lobby, added a cave bath, a stone-bed bath, a cold plunge and a history room. What Japanese guests come for is the water. The inn owns five sources flowing about 2,000 litres a minute, uses only a fraction of it, and sends it unheated and undiluted into every bath, every guest room's bath, and even the taps and showers; guests describe silky, slightly sulphur-scented alkaline water and baths open around the clock. Since reopening it rates 4.7 across 50 reviews on one major site and 4.61 on another, where the onsen (4.77) and dinner (4.71) are the top categories. Dinner is a 'mountain kaiseki' with no seafood — river fish such as amago and iwana, acorn noodles, Koshu beef on lava stone — and free room upgrades are reported again and again. The catches: the road in is long, closes in heavy rain or snow, and is busy with trucks for the Linear Chuo Shinkansen works; the central air conditioning can't be set by temperature; riverside terraces draw swarms of insects in summer; and some 2026 guests met inexperienced staff.