An attractive tourist destination! 5 recommended sightseeing spots in Shima Onsen, Gunma!

Shima Onsen, located in the northern part of Gunma Prefecture, has long been known as a “sacred spring that heals forty thousand (shima) ailments.” While Kusatsu Onsen, also in northern Gunma, is known for its highly acidic spring quality, Shima Onsen is characterized by its mild water. It is even used as drinking water and is especially known for its benefits in treating gastrointestinal ailments. During the Edo period, it flourished as a hot spring inn town, and in 1954, it was designated the first “National Health Resort.” But it’s not just the hot springs that are wonderful. Nestled deep in the mountains, Shima Onsen is surrounded by beautiful nature and offers many sightseeing spots. The hot spring town has a nostalgic charm and is also an attractive tourist destination. This time, we will introduce some of the sightseeing spots in Shima Onsen!

1. Sekizenkan

When visiting Shima Onsen, the one hot spring inn you absolutely cannot miss—and which is so famous it's not an exaggeration to call it a sightseeing spot—is Sekizenkan. It opened in 1691, during the era of Tokugawa Tsunayoshi, the fifth shogun known for the “Edict on Compassion for Living Things.” The fact that this hot spring inn has continued operating since then would surprise many people.

Looking into its notable visitors in the past, you’ll find names such as Shinpei Goto, who played a leading role in the reconstruction of Tokyo after the Great Kanto Earthquake; Hideki Tojo, prime minister during the Pacific War; and more recently, former Prime Minister Yasuhiro Nakasone. The inn comprises three wings—the “Main Building,” “Sansou,” and “Kasho-tei”—each added over time and each with its own distinct atmosphere. Particularly noteworthy is the “Main Building,” constructed at the time of its opening.

This wooden, three-story “Main Building” is the oldest wooden hot spring inn architecture in Japan and has been designated as a registered cultural property of Gunma Prefecture. Even more astonishing, it is said to be one of the models for the setting in Hayao Miyazaki’s film Spirited Away, making it a sacred spot for many tourists and Studio Ghibli fans. The hot spring itself exudes a sense of history you won’t find elsewhere. The “Genroku Bath,” built in 1930, features five bathtubs in a large bathhouse, uniquely designed with arched windows and no faucets.

This bathhouse, where you’ll feel as though you’ve stepped into another world, is truly worth seeing. In addition, there are open-air baths, large indoor baths, and private family baths, all ensuring a variety of bathing experiences. Since its founding as a therapeutic bathhouse, Sekizenkan has retained that strong ambiance to this day, making it a rare gem. They also offer guided tours of the buildings, hot spring experiences, and day-trip packages that include meals—definitely something to check out!

2. Lake Okushima

Shima Onsen is a sightseeing area where you can also enjoy outdoor activities. “Lake Okushima,” located just past Shima Onsen Town on National Route heading toward Niigata, is an artificial lake created by the Shima River Dam, completed in 1999. The color of the lake's water will leave anyone in awe.

It shines in a translucent blue that seems to go on forever, and the water quality is extremely pure. It’s said that this is because of the dissolved mineral content from the Shima hot springs. Canoeing is also available as an activity.

3. Shima’s Potholes

As you head north on National Route 353 from Nakanojo Town toward Shima Onsen, you’ll come across a spot where strange, large holes have formed in the riverbed of the Shima River. This sightseeing spot is called “Shima no Ouketsu” (Shima’s Potholes).

Ouketsu are holes carved out of hard riverbeds or banks when stones get trapped in depressions and swirl around with the flow of the river. In “Shima no Ouketsu,” you can see eight such holes of various sizes along a 130-meter stretch. These were formed over tens of thousands of years and have been designated as a natural monument by the prefecture. They’re easy to miss if you’re not careful, but just like the hot springs, they show us the mysterious power of nature.

4. Kamagafuchi

After passing the potholes, continue north on the national road toward Shima Onsen, and you’ll reach a point where the Shima River narrows between rugged rocks. This place is known as “Kamagafuchi” and has long been a famous scenic spot along the Shima River.

In the past, the powerful rapids of the Shima River made it a spectacular sight, but the construction of a hydroelectric plant and dam just upstream has drastically reduced the water volume, making the formerly dramatic scenery harder to see. However, when heavy rain causes the plant's dam to open, the area returns to its former glory as a scenic wonder. It could be called a “phantom” sightseeing spot.

5. Hinatami Yakushido Hall

Located at the farthest end of Shima Onsen, “Hinatami Yakushido Hall” is deeply connected to the origins of the area and is a key sightseeing spot that you should visit at least once. It was built in 1598 as a prayer for the continued military fortune of Nobuyuki Sanada, the elder brother of Yukimura Sanada, made famous by the NHK drama Sanada Maru.

Today, it is designated as an Important Cultural Property of Japan. Yakushi is a deity believed to heal all illnesses, and this hall highlights Shima Onsen’s roots as a therapeutic retreat rather than merely a tourist destination. The complex consists of the “Okoudo” hall, the “Yakushido” itself, and “Gomuso no Yu,” the original hot spring believed to be the origin of Shima Onsen. Though small, the hall is enveloped in serene quiet, with only the sounds of the nearby stream, making it a deeply peaceful place. A spiritual sightseeing spot that will cleanse your soul.

◎ Summary

We have introduced several sightseeing spots in Shima Onsen, Gunma Prefecture. Although there are many more places worth visiting, these five alone should give you a sense of Shima Onsen’s charm. Originally developed as a therapeutic bath resort, Shima Onsen also offers a range of nature-related sightseeing spots. In addition to the hot springs' amazing healing properties, the historical buildings and nostalgic atmosphere of the hot spring town create a wonderfully rustic vibe. Shima Onsen is more than just hot springs—be sure to explore everything it has to offer.