A five-minute ride down a 42-degree cable car to the bottom of the Iya gorge, where a self-flowing bath sits beside the river. Day use 7:30–17:00, cable car included. A member of the Secret Onsen Preservation Society.
Five minutes by car from the Kazurabashi vine bridge, the day-use bath of a large hotel at the mouth of the Iya Valley — the biggest bathhouse in Iya, with a rotenburo facing the green gorge, indoor pool and sauna. At ¥1,100 it's a cheaper, later-opening alternative to Hotel Iya Onsen's cable-car bath (¥1,900). 20 minutes by car from Oboke Station. Closed Tuesdays.
Five minutes by car from the Kazurabashi vine bridge, this popular Iya inn is famous for its 'sky open-air bath' reached by private cable car. Day bathing (¥1,200) runs 10:30–16:00; the goemon cauldron baths are for overnight guests only. A free sky footbath on the viewing deck is spectacular on mornings with a sea of clouds. With Hotel Iya Onsen it forms Iya's pair of 'cable-car onsen', ideal for a break while touring the valley.
A large day-use onsen next to the Naruto boat-race stadium, 10 minutes by car from the whirlpools and the Ōtsuka Museum of Art. The open-air bath, fed by the site's own natural spring, opens to Naruto's hills and sky; there are also a carbonated bath, pot tubs, a hot sauna, cold plunge and outdoor rest area. Open 8:00–24:00 (last entry 23:00), from early morning to late night; ¥750 weekdays, ¥900 weekends and holidays. The ground-floor restaurant is known for fresh fish — Naruto sea bream and sashimi at fair prices. Walkable from the Konaruto-bashi bus stop on the Tokushima Bus Naruto line. Irregular closures.
A hot-spring hotel on the banks of the Yoshino River in the Ōboke–Koboke gorge, where the water has carved through 200-million-year-old rock. The strongly alkaline simple spring — locals say it makes skin toner unnecessary — leaves skin smooth, and the gorge-facing main bath and open-air bath look out over the Koboke rapids, said to be Japan's wildest, and the mountainsides in their seasonal colours. Day bathing: adults ¥700, children ¥350, 12:00–21:00 (last entry 20:00); open daily, but on Saturdays, holidays and group-booking days it may close from 15:00, so check ahead. A convenient base for the Ōboke sightseeing boats, the yōkai museum and the drive to the Iya vine bridge; about 15 minutes on foot from JR Ōboke Station (pick-up available). Soap provided, towels for a fee.
A hot-spring resort in Kamiyama, a mountain town up the Akui River about an hour by car from Tokushima city, known for its newcomers and IT satellite offices. At its heart is the town-run bath 'Iyashi-no-yu', a contemporary building of local cedar and cypress notable for tatami mats laid throughout the bathroom, changing room and lobby. The sodium-chloride-bicarbonate cold mineral water feels mellow, then leaves the skin refreshed. Bubble bath, jet bath, waterfall massage, lie-down bath, herbal bath, sauna, cold plunge and a children's bath, with towels provided. Day bathing: adults ¥680, children ¥340, 10:00–20:00, closed the fourth Tuesday (open on holidays, Golden Week, Obon and New Year). The Kawasemi restaurant uses local produce, and private rest rooms and overnight stays are available. Combine with sudachi citrus, Amagoi Falls and Shōsan-ji, temple 12 of the Shikoku pilgrimage. About 60 minutes by Tokushima bus (Kamiyama line) from JR Tokushima Station to 'Kamiyama Onsen-mae'.
A town-run hot spring inn on the clear Katsuura River in Kamikatsu, Tokushima – the village famous for its 'leaf business' and zero-waste pledge – that welcomes day bathers. The simple sulfur cold spring is heated for the baths and has a faint sulfur scent and a slippery, smoothing feel. The open-air bath faces the stream and looks over fresh greenery, autumn colour and terraced rice fields, with an indoor bath and sauna alongside. Adults (junior-high and up) pay ¥650 and children from 3 to elementary age ¥350; open 10:00–20:00, closed the second Wednesday. The dining room serves Kamikatsu mountain vegetables, Awa-odori chicken and dishes garnished with the village's celebrated 'irodori' leaves, and stays combining the adjacent campground and Kamikatsu tea farms are popular. Free parking for 150 cars, coaches welcome. About 50 minutes (39 km) by car from central Tokushima or 80 minutes from Tokushima IC; by Tokushima Bus on the Kamikatsu line to the Tsukigatani Onsen stop near the terminus. Pair it with the Kashihara rice terraces and the RISE & WIN brewery.