The deepest catalog of Japanese onsen: the most advanced map in Japan, every facet recorded, a community of bathers, and a passport that earns you badges as you go.
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 is required to publish on their 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.
A swing inside the bath. Ride out over the water.
A bath carved into a natural cave or grotto.
A weak current massages the muscles. A Showa-era curiosity.
Soak in mineral mud, a Beppu specialty.
Buried under heated mineral sand, beside the sea.
A tap of source water you can drink for health.
Bathing types, water source, sauna, tattoo policy, day-use hours, kashikiri. Plus a vocabulary of rare highlights, from kakenagashi water to konyoku mixed bathing.
Rotenburo · Indoor bath · Sauna · Cold bath
Onsen water · Kakenagashi
Kashikiri · In-room onsen · Konyoku
Tattoo · Kids
Restaurant · Washing · Towel rental · Rest area · Parking
Cave · Swing · Boat · Mud · Sand · Electric · Drinking · Ganbanyoku · Steam · Jet · Foot · Utaseyu · Nuruyu
Real onsen, real photos. Tap any card to open the page.
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.
100 onsen visited.
An onsen in every prefecture of Japan.
From Hokkaidō to Okinawa.
Wrote 1,000 reviews.
Member of Japan's Hidden Springs Association.
All three sotoyu of Kusatsu.
All seven public baths of Kinosaki, in yukata.
All thirteen sotoyu of Nozawa, sealed.
Master of Beppu's onsen way.
Master of Wakayama's twelve baths.
The eighty-eight saints of Kyūshū's hot springs.
Master of the way of eggs cooked in onsen water.
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.
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.
A Kyushu-wide onsen stamp pilgrimage of source-quality springs across all seven prefectures; collect 88 stamps to climb its ranks.
