Matsuba Onsen Taki-no-Yu

Spring-source temperature

Not published on the main official text pages checked in 2026

Bathing temperature

Fixed bath temperature not published

Spring source

Matsuba Onsen natural radon spring; the individual source name is not published on the current main official text pages

Spring classification

The current main and onsen pages describe it as a natural radon spring; the facility overview uses the simplified term “mildly alkaline spring.” A current complete analysis report and legal classification were not confirmed on the main official pages, so older third-party descriptions of a mildly radioactive spring are not treated as current confirmed data.

pH

Not published

Flow rate

Not published

Water handling

The public baths and semi-open-air bath use natural radon spring water. Current main official text pages do not fully disclose water addition, heating, recirculation or disinfection for each public bath, so no overall free-flow claim is made. The current booking page states that all six private guest-room open-air baths use 100% natural radon spring water with recirculation and filtration; both details are retained.

Analysis date

Not published

Children under 12 cannot stay overnight, but children aged 3 and up can use the day bath at the listed child rate; these rules are separate. Tattoos, including tattoo stickers, are not allowed on the premises. Overnight-guest shuttle service requires advance reservation and may not match the requested time; do not treat it as an on-demand complimentary shuttle for individual day visitors.