Unazuki Onsen — Gateway Hot Spring to Kurobe Gorge

Unazuki Onsen (宇奈月温泉) is Toyama's premier hot spring resort town, nestled at the entrance to Kurobe Gorge where the Kurobe River emerges from the mountains. The town's onsen waters are piped 7km from Kuronagi Hot Spring deep within the gorge, maintaining a temperature of 90°C upon arrival — making Unazuki one of Japan's hottest source springs. The alkaline waters are renowned for skin-smoothing properties and are diluted to bathable 40–42°C at each ryokan.

The town stretches along the Kurobe River with traditional ryokan (Japanese inns) lining the riverbanks, many featuring outdoor rotenburo (露天風呂, open-air baths) with views of the gorge and mountains. Unazuki serves as the departure point for the Kurobe Gorge Railway, making it a convenient base for gorge exploration combined with onsen relaxation.

Unazuki's atmospheric riverside setting, quality hot springs, and proximity to Kurobe Gorge make it Toyama's top onsen destination. The town also features free public footbaths (ashiyu, 足湯) along the river, a riverside walking trail, and seasonal illuminations in winter.