Kusatsu Onsen Yubatake Central Pool

Kusatsu Onsen Yubatake — 'hot water field' — is the beating heart of Japan's most famous onsen, where 32,300 liters of strongly acidic sulfurous water per minute bubble from the central spring field, creating a 160-square-meter steaming tableau at the center of the onsen town that is simultaneously Japan's most visited thermal attraction and its most productive single geothermal spring source. The Yubatake's cooling wooden channels reduce the 53°C water to bathing temperature before distribution to Kusatsu's hundreds of inns and public baths, while the traditional yumomi dance performance — performed twice daily — theatricalizes the ancient technique of stirring hot spring water with long wooden paddles. The historic jizo-yu and goza-no-yu public baths at the Yubatake perimeter offer direct access to Japan's most powerfully concentrated therapeutic waters, recognized since the Edo period as effective against numerous chronic diseases.