Shioburo Hoyokan: Suo-Oshima’s Seawater Bath and What Is Open Now
Shioburo Hoyokan heats Seto Inland Sea water rather than using a natural spring. See current bath status, admission, hours and access on Suo-Oshima.
Summary: Shioburo Hoyokan is a bathhouse inside Green Stay Nagaura, known for heating seawater rather than drawing from a natural hot spring. After an equipment closure, service resumed on July 1, 2026 with the white-water bath, medicated bath, cold bath and sauna; the reopening notice said the saltwater bath would return separately. Confirm its status before making a special trip.
Checked: September 27, 2026
First, the current salt-bath caveat
The name Shioburo refers to a traditional bath made by pumping in seawater and heating it. Following equipment trouble, the Suo-Oshima Tourism Association announced that the bathhouse would reopen on July 1, 2026 with the saltwater bath still out of service; the white-water bath, medicated bath, cold bath and sauna were listed as available. A later town notice on August 13 announced that the saltwater bath had reopened. As several equipment notices appeared this year, confirm with Green Stay Nagaura at 0820-79-0021 if the salt bath is the reason for your visit.
That distinction matters: this is not a natural onsen. The seawater is heated on site; its saltiness does not make it a mineral spring. The surviving baths can still make a convenient post-cycle or post-hike stop, but the facility’s signature feature should not be assumed available.
What the bathhouse usually offers
The operator describes three main tubs: the seawater bath, a regular freshwater bath and a rotating refresh bath. There is also a sauna, individual washing stations and a second-floor lounge with views toward the Seto Inland Sea. During the current partial reopening, the two non-saltwater tubs and sauna are the ones named in the dated notice. The general facility page still describes the full arrangement, so a phone call is the safer way to check what is running on your date.
| Admission and extras | Price |
|---|---|
| Adult admission | ¥520 |
| Children aged 4 through elementary school | ¥300 |
| Children aged 3 and under | Free |
| Suo-Oshima residents aged 65 and over | ¥410 |
| Qualifying disability certificate reduction | ¥100 off the applicable fee |
| 11-visit adult pass | ¥5,230 |
| Small bath towel | ¥100 |
| Sauna bath-towel rental | ¥100 |
The operator asks visitors to bring their own towels. For comparison, Yuyu Land also charges adults ¥520, while Ryuzaki is ¥730 and has a natural saline spring. Towels are separate from admission.
Hours and location
The current published schedule is 10:00–20:00, with last admission at 19:30. Tuesday is the regular closing day, moving to the following day when it is a public holiday.
Summer hours are temporarily shortened; the old 21:00 closing time no longer applies.
Green Stay Nagaura is at 1144-1 Mugino, Suo-Oshima, near the island’s bridge entrance. By car, the facility gives an estimate of about 10 minutes after crossing Oshima Bridge and turning left. Its access page does not lay out a bus stop and walking route in the same detail. If you are not driving, ask staff which stop and final approach work on that day before committing to the trip; the no-car route guide covers the wider island connections.
The municipal bus map shows services in the broader Mukuno area, but a route passing nearby is not the same as a clearly documented first-time stop-to-door walk. If staying at Green Stay, using a bicycle or arranging a taxi from Obatake Station, the bath is easier to plan. Drivers have about 50 parking spaces listed for the complex. There is no outdoor bath; the bathing room has a sea-facing window, while the second-floor lounge is the place for a wider Seto Inland Sea view.
Yuyu Land and Ryuzaki Onsen are the nearby alternatives if you specifically want a confirmed natural hot-spring bath. Yuyu Land is the lower-cost option by Katazoegahama beach; Ryuzaki has the dark saline spring and bay-facing outdoor baths, with a separate caveat about the last published pool-by-pool spring-water update.
