Loaded with major ions — the essential minerals (Ca, Mg).
Buoyancy
Standard buoyancy
LowHigh
Soft water — natural, classic buoyancy.
BicarbonatesSodiumCalcium
Gyoda, in northern Saitama Prefecture near the Tone River, is celebrated for its remarkable concentration of ancient burial mounds including the Sakitama Ancient Burial Mounds site, home to eight large keyhole-shaped kofun tumuli from the fifth and sixth centuries and the famous Sakitama Inariyama Sword bearing a 115-character gold inscription dating to 471 CE. Gyoda Onsen Saitama draws on sodium and bicarbonate thermal waters from the geothermal resources beneath the north Kanto alluvial plain, providing warm restorative baths in a city whose extraordinary archaeological heritage represents some of the earliest documentary evidence of political authority and written language use in ancient Japan. The Sakitama Burial Mounds Historical Park, the Gyoda City Historical Museum housing remarkable Iron Age artefacts, and the local Gyoda tanuki raccoon dog festival create a distinctive cultural backdrop for thermal spa exploration in this historically significant northern Saitama city.
Insider tip — Gyoda sits on a flat alluvial plain north of Kita-Kanto and draws mild bicarbonate thermal water at 40°C from sedimentary aquifers below the rice-growing lowlands. The town is celebrated for its Oshi Castle ruins, one of Japan's premier castle sites, and the pairing of historical sightseeing with an evening sento soak is a local tradition. The water's smooth bicarbonate character soothes tired legs after a day of walking the earthworks. Gyoda's old silk-dyeing quarter nearby offers additional cultural depth for the curious visitor.