Yunotsu Onsen Yakushi-yu

A spring born of an earthquake — “all 5s” 100 % free-flowing water in a World Heritage port spa town

Yunotsu Onsen, in Oda, Shimane, is the spa town of the port from which the silver of the World Heritage Iwami Ginzan mine was shipped — the only onsen town in Japan included within a World Heritage zone, and a nationally designated preservation district of traditional buildings. In the middle of its narrow lanes of wooden inns and shops stands the source bath Yakushiyu. The spring is said to have burst from the ground in the great Hamada earthquake of 1872, earning the nickname Shin-yu, “earthquake bath”, and its sodium-calcium chloride water rises at about 46 °C and flows through the tubs 100 % untreated, with no heating or dilution. It is one of the few springs awarded the maximum “all 5s” in the Japan Spa Association’s natural hot-spring assessment. The bathroom is humble — one small indoor bath per gender — but the rim and floor of the tub are encrusted with thick brown mineral deposits that have grown like stalactites, visible proof of the water’s strength. Brown, iron-rich, salty and carbonated, it warms deeply; records note that it was once used for the convalescence of atomic-bomb survivors. The Taisho-era Western-style wooden building next door was the old bathhouse and is now Shin-yu Café Naizonojo, serving local food and coffee. The 2nd-floor and rooftop rest areas are free, with complimentary coffee, so you can cool down looking over the port’s rooftops. Adults ¥600, 9:00–21:00 (from 8:00 at weekends and holidays), open daily. Most visitors combine it with Iwami Ginzan (the Omori townscape and Ryugenji tunnel), and if you stay in Yunotsu, comparing it with the town’s other communal bath, Motoyu (hotter), is a pleasure for onsen fans.

Tips & cautions

- 9:00–21:00, from 8:00 at weekends and holidays. Open daily; last entry 20:30.

- The 46 °C source runs untempered — it is hot. Check the two tubs (hot / slightly less hot) and ease in.

- No soap or shampoo — bring or buy. Expect towels to turn brown.

- The bathroom is tiny — take turns in a group; when crowded, the neighbouring Motoyu (hotter, separate fee) is an option.

- Tattoos: small source bath with no confirmed policy — ask at the desk.

- Free rest on the 2nd floor and roof with complimentary coffee — allow time for it.

- Yunotsu Station to the spa town is a 15-minute walk (3 min by taxi); trains run every 1–2 hours — a timetable is essential.

- A day with Iwami Ginzan: Omori and the mine tunnel in the morning, a bath at Yunotsu in the afternoon, then a harbour stroll (the climbing kilns of Yakimono-no-sato are nearby).

Getting there

~15 min on foot or 3 min by taxi from JR Yunotsu Station (San’in Line), Yunotsu Ro 7-1, Yunotsu-cho, Oda, Shimane. ~1 h by JR from Izumoshi Station, ~20 min by car from Iwami Ginzan (Omori), ~1 h 20 min from Izumo Airport. Free parking, 30 cars. Tel. 0855-65-4894.