Nanki-Shirahama Onsen
- Location
- Shirahama, Japan
- Water type
- sodium chloride, bicarbonate
- Temperature
- 35 °C
- pH
- 7.5
Water profile
Soothing — neither hot nor cold, perfect balance.
Loaded with major ions — the essential minerals (Ca, Mg).
Dense, salty water — you float without effort.
Nanki-Shirahama Onsen is one of Japan's oldest and most celebrated hot spring resorts, located on the Kii Peninsula's southern coast in Wakayama Prefecture, where chloride-bicarbonate springs have attracted pilgrims and aristocrats since the Nara period when Emperor Monmu reportedly bathed here in the 8th century. The resort combines public communal baths including the spectacular Saki-no-Yu rotenburo — a rock-pool bath directly at the Pacific Ocean's edge where waves sometimes wash over bathers — with a wide crescent of white sand beach rare in Japan for its tropical character. Nanki-Shirahama's layered history as an imperial retreat, Shinto pilgrimage waypoint, and modern beach resort makes it one of Japan's most culturally layered onsen destinations.