Genroku Saigajuku Furutakiya

A 54-room, 330-year-old Iwaki-Yumoto inn with 100% free-flowing sulphur water, a ninth-floor open-air bath and its own nuclear-disaster museum — good-value and family-friendly, but it's a big, ageing concrete building, and 2026 reviews mention insects, a leak and crowded breakfasts

Furutakiya was founded in 1695 and is now run by the founding family's 16th generation; despite the long lineage, it's a modern multi-storey block of 54 rooms that climbs the hillside in two wings. After the 2011 earthquake and nuclear accident it became a relief depot, a volunteers' lodging and a dormitory for an evacuated high school, and in March 2021 the owner turned a former banquet room into the private Nuclear Disaster Archive Museum 'furusato', which guests can visit. The draw is the water: Iwaki-Yumoto's sulphur–sodium chloride–sulphate spring (pH 8.1, 59°C), which the inn says is cooled without adding water and never recirculated, in two large baths with hot and warm tubs and a ninth-floor open-air bath for staying guests, plus a retro sentō-style private onsen bath opened in August 2025. Japanese guests rate it 4.11 across 1,891 reviews on one major site (baths and dinner 4.15, facilities 3.91) and 4.0 across 1,617 on another. Bloggers who stayed in 2023 and 2026 loved the soft, sulphur-scented water, the book lounge with free drinks, the okami's flower arrangements on every floor and friendly staff. The complaints are about age and scale: in 2026 guests reported insects including a centipede, a dusty air conditioner and no one at the front desk at night (August), rain leaking into the old wing during a downpour and a room entered by cleaning staff before checkout (September), long queues at the breakfast buffet, a far-off car park and student groups filling the baths. One blogger posting in January 2026 found the dinner poor value. Two-meal stays run about ¥19,400–30,800 per person; room-only stays from about ¥5,000–6,000.