Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Effortless float
LowHigh
Dense, salty water — you float without effort.
SodiumChloruresBrome
Sakaide Onsen in Kagawa Prefecture lies at the Shikoku approach to the Seto Ohashi bridge complex, the world's longest series of railway and road bridges connecting the islands of Honshu and Shikoku across the archipelago of the Seto Inland Sea. Chloride-rich mineral waters emerge warm and strongly warming, prized for their ability to maintain body heat through cold winter months and ease muscle fatigue after physical labour. The town's industrial port character and its position at a major infrastructure gateway give Sakaide a distinctly workaday onsen atmosphere, refreshingly free from tourist polish.
Insider tip — Sakaide sits at the foot of the Seto Ohashi Bridge, one of the engineering marvels connecting Shikoku to Honshu, and its chloride-rich spring water reflects the brackish coastal geology of Kagawa's Seto Inland Sea shoreline. The bridge itself is visible from several bathhouse windows at night when its cables glow with illumination, creating an unexpectedly dramatic backdrop for a municipal bath. Salt waters here are noticeably warming, ideal after cycling the Shimanami Kaido if you have extended your route. The bathhouse retains a functional neighborhood character appreciated by regular commuters.
