Masutomi Onsen (Hokuto City)

Rising along a ravine that leads up toward Mount Mizugaki in the mountains of Hokuto City, Masutomi Onsen is a spa known for water rich in radium. Its distinctive reddish-brown water has long been enjoyed in the classic cure style, sinking in slowly for a long, unhurried soak in the mild, lukewarm bath.

Highlights

Clear mountain streams run around the hot spring area, framing a quiet backcountry landscape. The spa also sits near the trailheads for the celebrated peaks of Mizugaki and Kinpu, making it an easy base for anyone wanting to immerse themselves in nature.

Enjoying the Seasons

Early summer wrapped in fresh green and the autumn foliage that dyes the ravine red and gold are especially lovely and draw many visitors. Summer stays cool as a retreat from the heat, while winter offers stillness ideal for focusing on the cure.

Access and Basic Information

The spa lies at the end of a mountain road from the Sudama interchange on the Chuo Expressway by car. By public transport, access is by bus from stations such as Nirasaki on the JR Chuo Main Line, and services are limited, so checking timetables is essential.

A Quick Tip

The way of this spa is to settle in for a long soak in the mild water, so you can enjoy lingering without overheating. The surroundings are rich in mountain nature, so pairing your visit with hiking or a walk makes it all the more rewarding.