The Watarase Keikoku Line and the Appeal of Mizunuma Station
The Watarase Keikoku Line connects Kiryu Station in Gunma Prefecture with Mato Station in Nikko, Tochigi Prefecture. The line inherited the route and heritage of the former Japanese National Railways Ashio Line.
Between Kiryu and Omama, trains travel mainly through urban areas. Beyond Omama, the railway follows the upper reaches of the Watarase River through a dramatic valley landscape. From the train windows, passengers can enjoy changing scenery throughout the year, with fresh green foliage in early summer and colorful autumn leaves being particularly impressive.
Seasonal trolley trains also operate on the line. With open-air cars and a leisurely pace, these trains allow passengers to enjoy the valley scenery while feeling the fresh mountain air. Along the railway are historic sites and remains associated with the former Ashio Copper Mine, allowing visitors to experience both the natural landscape and industrial history of the region.
“Mizunuma-no-Yu,” a Natural Hot Spring at the Station
The highlight of Mizunuma Station is “Eki no Tennen Onsen Mizunuma-no-Yu”, a natural hot-spring facility located next to the inbound platform. Its location right beside the railway platform makes it exceptionally convenient for travelers who want to enjoy a bath before boarding their next train.
Large Baths and a Sauna for Relaxation
The bathing area includes both an indoor bath and an open-air bath. The indoor bathing area has a calm, wood-inspired atmosphere, while the gentle hot-spring water provides a relaxing way to unwind after traveling.
From the open-air bath, visitors can look toward the Watarase River and surrounding mountains. The changing scenery, fresh air, and sounds of nature create an atmosphere quite different from that of an urban spa.
The facility also features a sauna with the pleasant aroma of Japanese cypress and a cold-water bath supplied entirely by natural underground water. Alternating between the sauna and cold bath offers visitors another way to relax and refresh themselves.
Large Open-Air Bath and the “Komorebi-an” Rest Area
The large outdoor bath provides views toward the ridgeline of Mount Kojinyama. Visitors can soak in the hot spring while enjoying the changing light, breeze, and seasonal scenery of the surrounding mountains.
After bathing, the “Komorebi-an” relaxation area is a comfortable place to spend some time. Guests can use the space in the provided loungewear and relax in tatami rooms or on reclining beds. A wooden deck offers another peaceful spot where visitors can listen to birdsong and feel the mountain breeze.
Local Cuisine from the Mountain Village
The on-site restaurant, Satoyama Honjin, serves dishes featuring ingredients from Gunma Prefecture and the surrounding region. Menu highlights include Japanese black beef sukiyaki, okkirikomi—a traditional Gunma noodle dish—and grilled river fish.
Combining a hot-spring bath with a meal featuring local ingredients makes Mizunuma Station more than just a place to wait for a train. It can become a relaxing stop as part of a sightseeing journey through the Watarase Valley.
Mizunuma Village and Nearby Attractions
The area around Mizunuma Station is also home to Mizunuma Village, an outdoor leisure destination offering a variety of experiences. Visitors can enjoy sauna facilities, glamping, brunch at a café, and juwari soba made entirely from buckwheat flour.
For travelers who enjoy spending time outdoors, the surrounding area offers opportunities to experience the forests and mountains of Gunma at a leisurely pace. Nearby attractions include Hanamigahara Campground and Riheichaya Forest Park, which attract visitors particularly during the warmer months.
Historic and cultural sites such as Jokanji Temple, Ikouji Temple, and Koroze Gorge are also scattered throughout the area, making it possible to combine nature walks with visits to places of historical interest.
The History of Mizunuma Station
Mizunuma Station first opened in 1912 as Mizunuma Station of the Ashio Railway. After the railway was nationalized, it became a station on the Japanese National Railways Ashio Line. In 1989, the line was transferred to the Watarase Keikoku Railway.
During the 1950s, Mizunuma also served as an access point for sightseeing around Mount Akagi. The station became busy with visitors traveling toward the cable car of the Akagi Climbing Railway.
Although the station’s facilities and operating arrangements have changed over the decades, its role as a gateway to sightseeing in the surrounding mountains has continued.
The hot-spring facility itself went through periods of closure and reopening, supported by the local community. In 2025, it began a new chapter as “Eki no Tennen Onsen Mizunuma-no-Yu.” Following renovation and the participation of local businesses, the facility became a central attraction of Mizunuma Village and helped bring renewed activity to the area.
Station Layout and Travel Tips
Mizunuma Station is a ground-level station with two side platforms serving two tracks. It is an unmanned station, with trains operating toward both Kiryu and Mato.
The station is also a convenient stop for travelers exploring the Watarase Valley. Passengers holding a valid ordinary train ticket can make a stopover, allowing them to combine a railway journey with a visit to the hot spring and surrounding attractions.
A Journey Blending Nature, History, and Hot-Spring Relaxation
Mizunuma Station brings together three distinctive experiences: the charm of a scenic railway journey, the natural beauty of the Watarase Valley, and the relaxing waters of a natural hot spring.
For visitors, one of the most memorable experiences is stepping off the train and finding themselves surrounded by forests and mountain air before enjoying a relaxing soak. The sound of the Watarase River and the changing scenery of the valley create an atmosphere far removed from the bustle of Japan’s major cities.
For travelers exploring Gunma by train, Mizunuma Station offers a chance to slow down, enjoy the landscape, and experience a distinctive side of rural Japan where railway heritage, mountain nature, local cuisine, and hot-spring culture come together.