Beppu Onsen Hoyoland

Beppu Onsen Hoyoland is a small hot-spring bathhouse in the Myoban hot-spring district of Beppu, Oita, built around a mineral mud bath and a separate colloid (mineral clay) bath fed by water rising from underground. The facility also has a sauna. It runs as a straightforward day-use onsen, with walk-ins welcome and no membership required.

Bathing is the main activity: soak in the mineral mud, move to the colloid bath, then finish in the sauna. Children are admitted, though anyone not yet toilet-trained is asked to stick to the colloid bath and skip the mud. The site is open every day from 9:00 to 20:00.

Day admission runs ¥1,500 for adults, ¥1,100 for junior-high students, ¥600 for elementary-age kids and ¥350 for children five and under; no booking is needed for a simple soak. Hoyoland also rents basic rooms for an overnight stay — room only, no meals — and guests who stay over get round-the-clock access to the colloid bath while the mud bath keeps its regular hours. Same-day room reservations need a phone call before 4pm (email isn't accepted for same-day bookings), and everything on site, including the rooms, is cash only — no cards or electronic payment.