Myoken Ishiharaso

Seven private springs of fizzy, untouched water, a 1931 stone rice warehouse turned into river-side suites, and a riverbank bath under a great muku tree — Kyushu's finest onsen inn, if you choose your room carefully

Ishiharaso sits on the Amori river gorge, facing its sister inn Gajoen across the water. Founded in 1966, it's built around its water: seven sources on site, each feeding its own bath, a bicarbonate spring cooled through heat exchangers so the carbonation survives, with no added water, no reheating and no chlorine — guests describe the fizz, a faint iron smell and warmth that lasts. The showpiece is Ishikura, a 1931 rice warehouse moved stone by stone and reopened in 2007 as four river-side rooms with open-air onsen baths; in 2023 four main-building rooms were redesigned by architect Sei Takeyama. Japanese guests rate it 4.79 across 80 reviews on one leading site, with baths at 4.89, and 4.67 across 103 on another, and it took Fujingaho's onsen-inn grand prix in 2024. Kaiseki is served in semi-private booths in the warehouse basement, with a vast shochu list and a much-praised breakfast. The weak points: only 10 of 18 rooms have onsen in the room, mountain-side rooms face a busy national road, the cheapest rooms feel dated, the baths are reached by outdoor stairs, the riverbank bath closes when the river rises, and there's no free pickup since the shuttle taxi ended in March 2026. Expect about ¥42,000 per person with two meals in the main building and around ¥65,000 in Ishikura.