Shinyaba Onsen; Iwato Yu
Nakatsu, Oita, Japan
- Location
- Nakatsu, Oita, Japan
- Water type
- thermal, sodium chloride
- Temperature
- 40 °C
- pH
- 7.3
Water profile
Thermicity
Sedative
LowHigh
Relaxing — deep, immediate muscle release.
Mineralisation
Restorative
LowHigh
Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Shinyaba Onsen, with its Iwato Yu bath, is located in Nakatsu, Oita Prefecture. The thermal, sodium-chloride water flows at 40°C, with a near-neutral pH of 7.3. The facility includes an indoor bath, an outdoor rotenburo bath and a sauna.
Insider tip — 'Iwato Yu' (岩戸湯 — rock cave spring) at Shinyaba Onsen in Nakatsu city, Oita. 'Iwato' (rock cave) evokes the Ama-no-Iwato cave of Japanese mythology — where the sun goddess Amaterasu hid, plunging the world into darkness, and was coaxed out by the other gods' celebratory dance. Springs emerging from rock caves carry this mythological resonance. Nakatsu city is home to Nakatsu Castle and was birthplace of Fukuzawa Yukichi — the Meiji-era intellectual whose face appears on the 10,000-yen note.
Nearby
Frequently asked questions
How hot is the water?
The water runs quite hot here, around 40 °C — a sedative water that brings immediate muscle release.
What type of water is found here?
This spot features thermal & sodium chloride water.
What is the best season to visit?
The most favourable period for this spot is: Toute l'année.