Sugo Onsen Seizanso

Seizanso is one of a handful of inns at Sugo Onsen, a highland hot spring on National Route 107 near the border between Iwate and Akita prefectures. Sugo Onsen is a relatively young resort: the source was struck in 1967 while test-drilling for lignite coal. Despite its remote mountain-pass setting, the expressway and national highway make it unusually easy to reach. Seizanso itself is a small inn with nine guest rooms and capacity for 47 people, backed by a natural woodland park where witch hazel and skunk cabbage bloom in spring and wildflowers continue into autumn.

The water is a sodium chloride-sulfate spring, classified as a hypotonic alkaline hot spring. It is drawn from the Sugo Onsen blended source, a mix of Sugo No. 3 well and the Hidehira no Yu source, emerging at 76.4 degrees Celsius with a pH of 8.6 and a total mineral content of 1,616 mg/kg. The bath water carries a faint olive-green tint and, most distinctively, a petroleum-like aroma with a scorched edge that is rare in this part of Tohoku. Seizanso is the only inn at Sugo Onsen with a free-flowing open-air bath fed directly by the source.

The bathing area consists of separate indoor baths for men and women plus a garden open-air bath ringed by azalea shrubs. Day-use bathing costs 500 yen for adults and 300 yen for children, available from 9:00 to 20:00 with last entry at 19:30. Free parking for 30 cars is provided, and overnight stays with two meals start at around 8,000 yen.