6 Must-Visit Attractions in Kawarayu Onsen – A Historic Hot Spring Town Reborn by the Dam

Kawarayu Onsen is a traditional hot spring located in Naganohara Town, Agatsuma District, in the northwestern part of Gunma Prefecture. Known for its chloride-sulfate spring waters, its origins trace back to 1193, when the samurai lord Minamoto no Yoritomo is said to have discovered steam rising from the mountains during a hunting expedition.

In the past, Kawarayu Onsen thrived as a stopover for travelers heading to Kusatsu Onsen, serving as a gentle bath after soaking in Kusatsu’s highly acidic waters. However, with the long-anticipated completion of the Yamba Dam—over half a century in the making—the original hot spring town was set to be submerged.

Today, the entire area has been reborn along the lakeside, rebuilt with a new hot spring source and revitalized as a modern travel destination. In this article, we’ll introduce six recommended sightseeing spots around Kawarayu Onsen. Relax in the soothing hot springs and explore the charm of the Agatsuma region.

1. Ouyu, The Symbolic Public Bath of Kawarayu Onsen

Ouyu was once the largest and most central of the three public baths in the former Kawarayu Onsen town. With the closure of the old onsen area, Ouyu was relocated and now serves as the only public bath in the newly developed onsen district, continuing to be cherished by visitors. The prominent "Sasa Rindou" crest at the entrance, said to be linked to the legendary discovery of the hot spring by Minamoto no Yoritomo, has been a symbol of Kawarayu since the days of the original Ouyu.

The hot spring water is pleasantly hot with a subtle sulfur scent, gently relaxing both body and soul. Despite the aroma resembling the strong Kusatsu Onsen, Kawarayu’s spring has a neutral pH of 7.2, making it especially kind to the skin. One of its charms is that you can soak for long periods without discomfort—unlike more acidic springs. Even travelers staying in local ryokan inns make time to stop by and bathe here, as Ouyu is considered the very heart of Kawarayu Onsen.

2. Agatsuma Gorge

Agatsuma Gorge, once accessible on foot from the old hot spring town, is a stunning scenic spot often referred to as the “Yabakei of the Kanto region.” Especially during the autumn foliage and spring greenery seasons, the steep valley becomes a sea of vibrant reds and lush greens. Originally, the entire Agatsuma Gorge was slated to be submerged due to the Yamba Dam construction plan. However, thanks to strong opposition from locals and others, about three-fourths of it was preserved.

From the newly constructed parking area, visitors can descend the promenade to the valley floor, where they’ll encounter scenic spots one after another—like Shiraito Falls, Tochidō Falls, Bentenjima, and the twin peaks of Daihōrai and Shōhōrai. Among them, the view of the red-lacquered “Shishitobi Bridge” (Deer Leap Bridge) is particularly iconic and is one of the most photographed locations in Agatsuma Gorge.

3. Roadside Station Yamba Furusato-kan

Located at the entrance to Kawarayu Onsen from the Kusatsu side, Roadside Station Yamba Furusato-kan offers a perfect stop for travelers exploring the Agatsuma area of Gunma Prefecture. This popular roadside station features a wide selection of local produce and specialty souvenirs. One of the highlights here is the hot footbath—so warm that it quickly gets your feet blushing!

Its standout specialty is the increasingly popular Yamba Dam Curry—a unique and fun dish served on a plate partitioned with a ceramic dam-shaped divider, replicating the future image of Yamba Dam. Both the curry and rice come in generous portions, packed with large chunks of ingredients for a satisfying meal. Don’t forget to grab a dam card as a special memento to go with your Dam Curry experience!

4. Fudō Falls

Fudō Falls is a scenic waterfall located near the central Fudō Bridge, one of the three bridges—Yamba Bridge, Fudō Bridge, and Maruiwa Bridge—that span across the Yamba Dam area. The best viewpoint is from the Kawarayu Onsen side, at the foot of Fudō Bridge. While the waterfall was once viewed from below via a mountain trail near the old hot spring town, visitors can now enjoy a full panoramic view from an elevated angle.

With its abundant water flow, Fudō Falls offers a refreshing sight in summer, surrounded by lush greenery. In autumn, the vivid contrast between the fiery red leaves and the pure white stream creates a breathtaking scene. Though it requires a short walk, the falls are accessible from the new Kawarayu Onsen Station or the nearby hot spring town. It’s a perfect side trip during your stay in the area.

5. Fudō Bridge

Fudō Bridge is one of the three bridges scheduled to span the Yamba Dam. With a total length of approximately 590 meters, it has gained attention as the world’s first “steel-concrete composite truss extradosed bridge.”

Before the reservoir begins filling, the bridge towers over the deep valley below—an astonishing sight. It’s quite surreal to think that this stunning view will soon be submerged under the dam’s water. This breathtaking view of the Agatsuma Gorge is something you can only witness now, so don’t miss it! If you're driving, it's recommended to park either at the Fudō Waterfall viewpoint or at the nearby roadside station, and then enjoy a walk back to your favorite spot.

6. Tarusawa Tunnel

The Tarusawa Tunnel is a unique and historically significant tunnel that once belonged to the former JR Agatsuma Line, running along the scenic Agatsuma Gorge in Gunma Prefecture. Measuring only about 7.2 meters in length, it holds the title of Japan's shortest railway tunnel ever constructed. However, after the realignment of the Agatsuma Line, it was retired from active use. The title of the shortest active railway tunnel now belongs to Kawajiri Tunnel (8.7 meters) on the JR Kure Line.

Just a short walk from the tunnel toward the Kusatsu direction, visitors will find a small parking area, where they can view this post-war industrial heritage, which was completed in 1946 (Showa 21). While walking inside the tunnel is not allowed, benches and information boards nearby make it an intriguing stop for railway enthusiasts and casual tourists alike.

◎ Summary

Although the former Kawarayu Onsen town was submerged due to the completion of the Yanba Dam, a new area is now embracing fresh tourism opportunities. Every year on January 20th, the unique and lively "Yukake Festival" is held, where numerous participants wearing traditional fundoshi (loincloths) splash each other with Kawarayu's hot spring water, shouting joyfully, “It’s a celebration!” Kawarayu Onsen has long been cherished as a legendary hot spring, still attracting passionate fans today. Northern Gunma Prefecture is home to many hot springs, but if you're looking for water that’s both hot and gentle on the skin, be sure to experience Kawarayu Onsen at least once.

Search

Customer Support

Manage Reservation(s)

Search

Customer Support

Manage Reservation(s)

6 Must-Visit Attractions in Kawarayu Onsen – A Historic Hot Spring Town Reborn by the Dam