Nishiura Onsen
- Location
- Nishiura, Aichi, Japan
- Water type
- sodium chloride
- Temperature
- 41 °C
- pH
- 7.3
Water profile
Relaxing — deep, immediate muscle release.
Loaded with major ions — the essential minerals (Ca, Mg).
Dense, salty water — you float without effort.
Nishiura Onsen opened in 1953 on the scenic Nishiura Peninsula jutting into Mikawa Bay in Gamagori City, Aichi Prefecture, establishing an iodine-rich thermal resort that grew into one of the anchor springs of the Gamagori Onsenkyo cluster alongside Mitaya and Katahara onsens in one of Aichi's most developed coastal resort zones. The bay-facing peninsula position gives Nishiura a distinctive coastal thermal character, where the iodine content—derived from ancient marine sedimentary geology beneath Mikawa Bay—is enjoyed with panoramic views across the sheltered inland waters of the Pacific-facing Mikawa coast. The spring's post-war establishment and rapid growth into a recognized resort reflects the central role that onsen development played in Japan's Showa-era reconstruction of leisure and tourism infrastructure.