The most advanced map of Japan's hot springs. Follow the stamp tours and meguri, earn badges, and keep a personal onsen journal. Built by bathers, every place checked by hand.
An official onsen pilgrimage across Wakayama: collect stamps from its twelve onsen areas to earn the Mastery Card.
Three municipal day-use bathhouses in Kusatsu Onsen, all pure source-water, linked by one no-expiry wooden tegata pass.
Seven public bathhouses in the willow-lined onsen town of Kinosaki, where the whole town is the inn.
Nine public bathhouses up the lane of Shibu Onsen in Nagano, each said to be good for a different ailment. Soak through all nine, stamp a prayer towel, and finish at the hilltop temple.
A pilgrimage-style stamp rally over the Kii Peninsula's sacred routes, with a bathing circuit across Wakayama, Osaka, Nara and Mie.
The wooden bath-hopping pass of Kurokawa Onsen, a Kumamoto village run as a single inn; one pass opens any three rotenburo.
For most onsens in our catalog, you'll find the full water chemistry: the spring type, pH, temperature, tonicity, dominant ions, color, taste and smell, and the conditions Japanese medical authorities recognize the water for. Everything an operator must publish on their water-analysis certificate (bunsekisho, 温泉分析書), laid out so you can actually read it.
Hydrogen-Aluminum Sulfate-Chloride spring
An acidic sulfur–sulfate source — hot at the wellhead, with a strong sour taste and the unmistakable sulfur note. Drains the skin of oils; recommended after a long day.
Five-star ratings and written notes from people who actually went.
From lobby signs to the bath itself, uploaded by visitors.
Every submission and edit checked by a moderator before it goes live.
Real onsen, real photos. Tap any card to open the page.
Mixed bathing (konyoku, 混浴) explained: where to find it, what to expect, and the etiquette that keeps it relaxed.
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Live policy data, a tattoo-friendly map, cover stickers, and the right phrases.
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A rare, playful feature: swings inside the bath, listed and mapped.
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