Kuroiso Onsen Nasu
- Location
- Nasu, Tochigi, Japan
- Water type
- sulfurous
- Temperature
- 44 °C
- pH
- 6.5
Water profile
Relaxing — deep, immediate muscle release.
Rich in active gases or metals — a strong mineral character.
Soft water — natural, classic buoyancy.
Kuroiso Onsen Nasu is located in the Kuroiso district of Nasushiobara City, Tochigi Prefecture, at the southern gateway to the Nasu Highland resort area — the gateway town where travellers arriving from Tokyo disembark from the Tōhoku Shinkansen to reach the Nasu hot spring resorts, the imperial family's summer villa, and the natural grasslands and volcano of Nasudake. The chloride-rich thermal waters draw from the deep alluvial and volcanic geology of the Nasu piedmont, providing warm saline mineral bathing accessible to visitors exploring the full range of Nasu's geothermal resources — from the intensely sulphurous Nasu Yumoto to the more restrained mineral waters of the highland plateau. Kuroiso's position as a transport hub and commercial centre makes it a convenient base for day-tripping to Nasudake's hiking trails, the Tsutsujigaoka azalea hillsides that bloom pink in May, the Nasu Animal Kingdom, and the Nasu Imperial Villa's garden — combining accessibility with entry to one of the most geothermally active resort areas in the Tokyo metropolitan region.