Recommended onsen in Osaka

About 30 minutes by car inland from Kansai International Airport, Matsuba Onsen in Kotsumi, Kaizuka, lies along the Kogi River valley and draws radon-bearing water from the granite beneath the grounds. The source is a cool 26.8°C and is pumped at 83.3 liters per minute. Sodium, chloride and bicarbonate lead its chemistry, yet total dissolved solids are a modest 0.729 g/kg, and its 236.8 Bq/kg of radon classifies it as a simple weak radioactive spring, known locally for warming the body and keeping it warm.

Named 'Himorogi,' an ancient term for a sacred space, this spring quietly emerges as if to purify the hearts and bodies of its visitors. The slightly alkaline water, with a pH of 8.1, feels gentle on the skin, offering a smooth sensation akin to soaking in a beauty serum. Combining the properties of both a chloride and bicarbonate spring, it provides lasting warmth and a silky skin feel after bathing. This onsen gently embraces those seeking to reset from the daily hustle and bustle or wishing to improve their skin's condition.

Said to have flowed since the Nanboku-cho period, this Amami spring is remembered in the tale of a "paradise bath" that soothed pilgrims bound for Mount Koya. Light in dissolved minerals, it is a radioactive spring carrying radon and a touch of free carbon dioxide. It suits travelers who trace the old Koya Kaido road and want a quiet soak by a clear stream.