Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
BicarbonatesSodiumCalcium
Mihama Thermal is a coastal onsen facility in the town of Mihama, nestled between the pine-fringed shores of Wakayama Prefecture's central coast and the forested hills descending toward the Pacific. Its thermal water offers the warming mineral immersion typical of the Kii Peninsula's rich underground hydrological network, prized for easing joint stiffness and fatigue after outdoor excursions. The quiet seaside setting and proximity to rural Wakayama farmland make Mihama Thermal a peaceful retreat for visitors seeking authentic regional hot spring culture along one of Japan's most historically layered coastlines.
Insider tip — Mihama sits on the serene southern coast of Wakayama where the Kii mountains tumble almost directly into the Pacific, and its bicarbonate springs reflect that rugged geology. The water has a pleasantly slippery texture that moisturizes deeply, popular with local fishermen who swear by its restorative effects after long days at sea. The small bathhouse is surrounded by mandarin orchards that perfume the air in autumn. Sunset views from the outdoor tub across Tanabe Bay are among the most quietly spectacular on the Kii Peninsula.
