KAI Enshu

Hotel Kikusuitei

浜名湖かんざんじ温泉 ホテル鞠水亭

A plain Shōwa-era onsen inn on Lake Hamana where every room faces the water, dinner is a Yufuin-designed kaiseki with eel or abalone, and cheap weekday bookings are often upgraded — but the baths are recirculated and shared with day visitors, and the building shows its age

Lake Shikotsu Tsuruga Bessou Ao no Za

しこつ湖鶴雅別荘 碧の座

Hokkaido's all-inclusive lake retreat: 25 suites of 100㎡ or more, each with an open-air onsen bath, and drinks from champagne to craft gin included — book a high floor, because the view from the cheapest rooms takes in the road

• Habitaciones con onsen privado

Shima Onsen Kashiwaya Ryokan

四万温泉 柏屋旅館

A 14-room retro-modern inn where three private open-air baths are free, unbooked and usable as often as you like, with a noon check-out — but it's a wooden house with steep stairs, no lift and thin walls, and most rooms have no bath of their own

• Habitaciones con onsen privado

Shima Tamura

四万たむら

A bath-keeper's inn since 1563 with seven free-flowing baths from its own riverbed sources — a mixed bath in the river, a waterfall-view open-air bath, a pebble-floored bath where the spring rises underfoot — in a big, ageing, maze-like building

• Ryokan históricos

Shima Onsen Toshimaya

四万温泉 豊島屋

A 15-room riverside inn whose every bath — shared, private and in eight of the rooms — runs on its own springs with no water added, no heating and no recirculation; the catch is no lift, a modest dinner for the price and signs of thin staffing

• Habitaciones con onsen privado

Shima Yamaguchikan

四万やまぐち館

Un gran ryokan junto al río con estética retro de la era Shōwa, cuyos dos largos baños al aire libre están justo sobre el cristalino río Shima — ven por el agua y por el kamishibai nocturno de la dirección del ryokan (okami), no por la comida ni por la tranquilidad