Tanoharu Onsen

Three hundred years by the river

Tanoharu opened far back in the Kamakura period, where hot water welled up from the bed of the Tanoharu River; remains from the Jomon era at the site suggest the water was used long before that. It came into its own in the Edo period as a tojiba, a cure-bathing village, where samurai of the Hosokawa domain came to heal wounds and recover, a history often counted at around three hundred years. In 1964 it was named a National Health Resort together with neighbouring Kurokawa and Manganji. Where Kurokawa next door is a styled, much-visited onsen town, Tanoharu stays small and sleepy: a handful of riverside inns rather than a strolling street.

Fireflies over the baths

The water rises hot (sources put the wellhead anywhere from the mid-50s to over 70°C) and is logged as a sodium chloride–sulfate–bicarbonate spring, simplified by the prefecture to an alkaline bicarbonate water, clear and kind to skin. The benefits cited run to neuralgia, rheumatism, muscle and joint pain, and the bijin skin-softening the area is known for. The signature is seasonal: in early summer, fireflies drift over the open-air baths along the river while kajika frogs call from the rocks, the scene the area is most often pictured by.

The inns

Roughly five inns line the river's west bank. Tairoukan is the anchor: a riverside ryokan past its hundredth year, with eight baths free to guests, among them a waterfall-view bath, a wooden barrel bath, and a cauldron-style goemon bath, all reservable for private use; it served as a location for a 1976 entry in the Otoko wa Tsuraiyo "Tora-san" film series, and still displays the posters. Ryukeien is a small six-room inn on free-flowing source water with five private baths. A source landmark called the Jigoku Genyu, "hell's source bath," where very hot water rises straight from the ground, remains in the area.