A municipal public bath two minutes from Bandai-Atami Station. Two pools of free-flowing spring water — a lukewarm one at about 36°C and a hot one — with silky alkaline water made for long soaks. Unusually, admission is highest in the morning and drops to ¥400 from 14:00 and ¥300 from 16:00. No towels or soap; bring your own.
Twenty-five minutes by local train from Fukushima, the emblematic communal bath of Iizaka Onsen, where the poet Basho is said to have bathed. Rebuilt in 1993 as a faithful copy of one of Japan's oldest wooden bathhouses, its granite tub runs with free-flowing spring water above 45°C. Locals don't cool it with tap water; visitors get guidance. ¥400, from 6 am. No soap or shampoo. Start here for a crawl of the town's nine public baths.
Thirty minutes by car from Fukushima city, the communal bath of Takayu Onsen at 750 m on Mt. Azuma. Every bath is open-air, filled with milky-white sulfur water that is neither diluted nor heated. There's a timber men's bath, a rock women's bath and a reservable private rotenburo. A ¥500 gateway to a spa town that has kept its water free-flowing for 400 years. Closed Thursdays; one-hour limit. At the foot of the Bandai-Azuma Skyline — ideal with an autumn drive.
An inn with its own spring midway along the Yukawa gorge, where the ryokan of Higashiyama Onsen line the river 10 minutes by car from central Aizu-Wakamatsu. Day visitors get the riverside open-air bath facing a waterfall and the main bath for ¥1,100 including a small towel, 13:00–20:00. Private panoramic baths (¥1,650) and lunch packages are also offered. With 1,300 years of history, Higashiyama was the retreat of artists such as Takehisa Yumeji and poet Yosano Akiko — a natural finish to a day at Tsuruga Castle and the Byakkotai sites on Iimoriyama. Reception hours may shorten when busy.
A public bathhouse (doubling as a self-catering lodge) in the centre of Dake Onsen, about 600 m up the slopes of Mt Adatara. The acidic spring is rare nationally; piped roughly 8 km from the source, the water cools on the way and arrives milky white with a slight tingle. The basement bath is indoor only but 100% free-flowing. Day use 10:00–19:00 (last entry), ¥400 for adults, closed Tuesdays. The sloping resort street keeps traces of the town's playful 'Nikoniko Republic' era and has a free foot bath. About 25 minutes by bus from Nihonmatsu Station; popular with hikers coming down Mt Adatara and skiers.
The signature 92-room ryokan of Dake Onsen, at about 600 m on the flank of Mt Adatara. The source is piped 8 km from near the Kurogane hut in the mountains and cools naturally in a yubatake on the way, arriving at bathing temperature — a nationally rare acidic spring with a bracing, skin-tightening feel. The 'Haiku' main bath and the 'Moon-viewing' and 'Blossom-viewing' open-air baths look out on the Adatara range. Day bathing: adults ¥1,000, children ¥500, 12:00–20:00 (last entry 19:30; from 15:00 on Wednesdays, 12:00–16:00 on Saturdays and days before holidays), with entry limits when crowded. Day plans with a buffet are popular too. About 15 minutes by car from Nihonmatsu IC or 25 minutes by bus from JR Nihonmatsu Station. Combine with the cherry-tree avenue of Himalaya-dōri and Chieko's hometown sights.
The public bath at the centre of Tsuchiyu Onsen, a spa village in the fold of the Azuma range about 40 minutes by bus from Fukushima Station. Rebuilt in 2018 in fragrant timber, it faces the Arakawa mountain stream. The alkaline bicarbonate water is used free-flowing without heating or recirculation — clear and soft but decidedly hot, so adding cold water to taste is the local custom. Besides separate indoor baths there is a private bath (¥1,500), handy for families and couples. Adults ¥500, children ¥250; open 09:00–21:00 (last entry 20:30), closed Tuesdays (open over New Year). The village has foot baths, workshops making Tsuchiyu kokeshi dolls, the steaming Arakawa source and another communal bath, Kajika-no-yu, so a stroll with a kokeshi-painting session fills a pleasant half day. 82 free parking spaces. About 20 minutes by car from Fukushima-nishi IC, and a convenient gateway to the Bandai-Azuma Skyline.
The largest and most storied inn of Ashinomaki Onsen, a spa strung along the Aga (Ōkawa) river gorge south of Aizu-Wakamatsu. Its soaring lobby 'floating stage', where live shamisen echoes each evening, became famous for resembling the bathhouse of a beloved animated film. The star is the 'superb-view open-air bath' cantilevered over the gorge, looking down on the river and the mountainsides through the seasons – spectacular in autumn colour and winter snow. The clear sodium-calcium sulfate-chloride water warms deeply and holds its heat. Day bathing runs 11:00–15:00 (reception until 14:00) for ¥1,800 per adult and ¥900 for ages 3–12, tax and bathing tax included with a face towel, open every day. The 'sky open-air bath' can be booked privately for ¥3,300 per 45 minutes (two slots each at 13:00 and 14:00), and day plans with lunch in a private room from ¥5,500 are popular. Free parking for 150 cars, pick-up from Ashinomaki-Onsen Station on the Aizu Railway, or about 40 minutes by car from Aizu-Wakamatsu IC via Route 118. A natural stop between Ōuchi-juku and the Tō-no-Hetsuri cliffs.