Do you love hot springs (温泉 onsen)? They are one of the main draws for visitors flocking to Japan each year, and although they can be found in many areas around the country, one particular prefecture famous for hot springs is Gunma (群馬県). The landlocked prefecture is home to several amazing hot springs, but what’s more, there is one train line that will bring visitors close to them.
The Agatsuma Line (吾妻線) is a train line that traverses the valleys of Gunma and follows the Agatsuma River. With a total length of 55.6km, it connects JR Ōmae Station (JR大前駅) and JR Shibukawa Station (JR渋川駅), and trains on the line also run through the Jōetsu Line (上越線 Jōetsu-sen) to/from JR Takasaki Station (JR高崎駅 Takasaki-eki). The Agatsuma Line is known for the number of hot springs near its route, so if you’re visiting a hot spring town in Gunma, you can access it via this line.
For this article, we are exploring the “hot spring” line and the hot spring towns that are located nearby, and we shall discover the beauty of the prefecture’s seasons and nature along the way. If you love riding trains and soaking in hot spring baths, then this article is for you.
A train ride to Gunma’s famous hot springs
As mentioned earlier, the Agatsuma Line is noted for its access to several Gunma’s beloved hot springs. The trains that run on the line are the 211 series, which is used for the ordinary train service, and the 651 series, which is used for the Limited Express Kusatsu train service that runs between JR Ueno Station (JR上野駅 Ueno-eki) in Tokyo and JR Naganoharakusatsuguchi Station (JR長野原草津口駅). Thanks to this limited express train service, Tokyo dwellers can reach Gunma’s hot springs directly.
Visitors can hop on the train and get off at selected stations to visit the many hot springs located close to the line. Let’s explore these stations, and check out the hot springs that you can visit from each of them.
① JR Shibukawa Station (JR渋川駅)
First up on the Agatsuma Line is JR Shibukawa Station. Originally built in 1921, the station is a terminus on one end of the line, with JR Ōmae Station on the other. Visitors can get off here when they are heading to one of Gunma’s most loved hot spring towns.
Ikaho Onsen (伊香保温泉)
Just a 20-minute bus ride away from JR Shibukawa Station is Ikaho Onsen, which is often regarded as one of the top four hot spring towns of Gunma, with the other three being Kusatsu Onsen, Shima Onsen (四万温泉), and Minakami Onsen (水上温泉). Tucked away in the mountains of Gunma, the traditional hot spring town has a long history that dates back to the 9th century, and is loved by many visitors for its cosy ambience.
What’s unique about Ikaho Onsen is that it is built on the slopes of Mount Haruna (榛名山 Haruna-san). Upon reaching the town, visitors will come across a flight of stone steps stretching approximately 300m that leads up to the town centre. Built in 2010, the stone steps have become part of Ikaho Onsen’s identity, and a cherished landmark among visitors.
Here’s a tip: don’t just climb the steps in haste. Take your time to observe the different writings engraved on them, such as poems from Yosano Akiko (与謝野晶子), and wishes for prosperity for the town. There are 365 steps altogether, and one of them even states “I want the hot spring town to become crowded 365 days a year”!
If there’s one thing that Ikaho Onsen is famous for, it’s the hot spring water, which is rich in iron and minerals, and is known for its healing properties. There are two different sources of the hot spring water: one is Kogane-no-Yu (黄金の湯 Golden Water), known for its reddish-brown iron-rich water, and the other is Shirogane-no-Yu (白金の湯 Silver Water), which is more transparent.
Try the hot spring waters and feel the difference yourself; you can learn how they can have different effects on your body firsthand.
Want to witness a local festival? Then you will be glad to know that Ikaho Onsen has its own festival named the Ikaho Matsuri (伊香保まつり), which is held from 18 to 20 September every year. During this period, visitors will get to see participants hauling 11 taru-mikoshi (樽神輿 portable shrines made from sake barrels) up the town’s stone steps and towards Ikaho Shrine with others dancing and playing traditional festival music.
Ikaho Matsuri (伊香保まつり)
Dates: 18–20 September
Venue: Ikaho Onsen’s town centre
Access: 10-minute walk from Ikaho Bus Terminal
While exploring Ikaho Onsen, why not venture out to see other scenic spots? Just south of the hot spring town’s centre is Kajika Bridge (河鹿橋 Kajika-bashi), a lacquered vermillion bridge that is surrounded by Shibukawa’s pristine nature. The bridge is highly popular among visitors for its picturesque landscape, and becomes a magnificent sight, especially in autumn.
From late October to mid-November, the Kajika Bridge Autumn Illumination (河鹿橋紅葉ライトアップ) is held when the bridge is lit up at night amidst the red, orange and golden autumn foliage, rendering the entire area simply magical. Be sure to take note of this event if you are in Ikaho Onsen during the season!
Kajika Bridge (河鹿橋)
Address: Ikaho, Ikaho-machi, Shibukawa, Gunma 377-0102
Access: 15-minute walk from Ikaho Onsen’s town centre
Ikaho Onsen (伊香保温泉)
Address: Ikaho, Ikaho-machi, Shibukawa-shi, Gunma
Access: 25-minute bus ride by *Kan-etsu Kotsu from JR Shibukawa Station
(*Note: The bus service is not covered by JR East Passes.)
② JR Nakanojō Station (JR中之条駅)
Next, we move on to JR Nakanojō Station. It is a modest railway station with three platforms where only two are in use, and here is where visitors can get off to head to not one but two hot spring towns in the area.
Shima Onsen (四万温泉)
JR Nakanojō Station is the stop for visitors to get off and head to Shima Onsen, the second of the top four hot spring towns of Gunma. It is also one of the oldest hot spring towns in Japan, and its name “四万” (yon-man = shima) means forty thousand, as it is said that bathing in its mineral-rich hot spring water can cure up to 40,000 ailments!
The town has some hot spring inns, each offering its own unique hot spring baths and brand of hospitality, but do you know that there is an inn here that is said to have inspired the main setting for the critically acclaimed Studio Ghibli movie “Spirited Away” (千と千尋の神隠し Sen to Chihiro no Kamikakushi)? Sekizenkan (積善館) is a hot spring inn in Shima Onsen that has been patronised by many dignitaries and famous writers over the years. It is often said to be one of the models for the bathhouse where protagonist Chihiro was forced to work in the animated movie.
The inn is made up of three buildings—the main building, the Sansō (山荘) building, and the Kashōtei (佳松亭) building—and each of them was built at different times in history. The main building, in particular, was originally built in 1691, making it the oldest wooden hot spring inn in Japan.
It also houses Genroku no Yu (元禄の湯), a quaint Romanesque bathhouse built during the Taishō Era. Featuring large arched windows, the bathhouse invokes nostalgia, hearkening back to an era when Western architecture married traditional Japanese design. The main building and the bathhouse have also been designated as an Important Cultural Properties (重要文化財).
Visitors stepping into the inn would feel like they have travelled back in time, as the buildings exude an old-world atmosphere that has been carefully preserved since their construction. If you’re looking for an unforgettable stay, be sure to take note of this one, especially if you’re a Ghibli fan!
Sekizenkan (積善館)
Address: 4236 Shima-ko, Nakanojo-machi, Agatsuma-gun, Gunma 377-0601
Access: 40-minute bus ride by *Kan-etsu Kotsu from JR Nakanojō Station
(*Note: This bus is not covered by the JR East Pass.)
Shima Onsen is renowned not only for its amazing hot spring water, but also for its serene natural atmosphere. With the placid Shima River (四万川) flowing through the rustic town, and surrounded by nature that changes colours according to the season, the town is a gorgeous respite for visitors who would want to get away from the bustling city life.
Want to admire the natural splendour further? Head up north of the town and you will come upon Lake Okushima (奥四万湖), a picturesque lake where the Shima River flows from. It is a reservoir formed by the Shimagawa Dam, and visitors will be enthralled by the brilliant cobalt blue colour of the lake, which is locally known as “Shima Blue”.
The lake’s brilliant colour is most pronounced during spring, when the surrounding mountain’s snow melts and flows into it. Coupled with colourful surrounding foliage that changes colours according to the season, the lake looks like it comes straight out of a painting.
Shima Onsen (四万温泉)
Address: Shima, Nakanojo-machi, Agatsuma-gun, Gunma
Access: 40-minute bus ride by *Kan-etsu Kotsu from JR Nakanojō Station
(*Note: The bus service is not covered by JR East Passes.)
Sawatari Onsen (沢渡温泉)
There is another hot spring attraction that can be accessed from JR Nakanojō Station, and that is Sawatari Onsen. Like Shima Onsen, this hot spring retreat is easily accessible with a short bus ride from the railway station.
But unlike Shima Onsen or other more popular hot spring towns near the Agatsuma Line, Sawatari Onsen is quieter and more idyllic, as the town only has a handful of hot spring inns. It is known for its hot spring water rich in minerals such as calcium and sodium sulphate, which are said to have skin-beautifying effects.
It is also said that Sawatari Onsen has a history that goes back as far as the Jōmon Period (around 1,000 BC), and that it first opened as a hot spring town in the late 12th century. Since then, it has been visited by many prominent figures and writers throughout different eras, and many visitors have vouched for the town’s warm hospitality and serene ambience.
Sawatari Onsen (沢渡温泉)
Address: Kamisawatari, Nakanojō-shi, Agatsuma-gun, Gunma
Access: 20-minute bus ride by *Kan-etsu Kotsu from JR Nakanojō Station
(*Note: The bus service is not covered by JR East Passes.)
③ JR Kawarayu-Onsen Station (JR川原湯温泉)
For our third station, we look at JR Kawarayu-Onsen Station. Originally built in 1946, the station was initially named Kawarayu Station (川原湯駅) but when the Yanba Dam (八ッ場ダム Yanba-damu) was constructed, the train line section between JR Iwashima Station (JR岩島駅) and JR Naganoharakusatsuguchi Station changed course, and Kawarayu Station was relocated to a hill further west of the original spot in 2014. In 1991, the station finally adopted its current name.
Kawarayu Onsen (川原湯温泉）
The station is the stop for Kawarayu Onsen, a small hot spring town with more than 800 years of history. The town was relocated in 2014, together with the railway station, following the construction of the Yanba Dam. Its concept is to be a “hot spring town where you can walk while gazing at the scenery”, so visitors will be pleasantly surprised by the serenity of the surroundings. The town makes for the perfect place for those seeking a more quiet and peaceful hot spring getaway, and if there is one place they must pay here, it’s the Kawarayu Onsen Ōyu Kaikan (川原湯温泉王湯会館).
Kawarayu Onsen Ōyu Kaikan is a public bathhouse that has been a proud landmark for the locals for generations. Although the original building was remodelled following its relocation, its original entrance design is retained. The hot spring water here is also known to be beneficial for people with rheumatism and joint pain.
Kawarayu Onsen Ōyu Kaikan (川原湯温泉王湯会館)
Address: 234 Kawarayu, Naganohara-cho, Agatsuma-gun, Gunma 377-1302
Access: 20-minute walk from JR Kawarayu-Onsen Station
④ JR Naganoharakusatsuguchi Station (JR長野原草津口駅)
Then, we have the JR Naganoharakusatsuguchi Station, perhaps the most prominent railway station on the Agatsuma Line. Built in 1945, the station was originally named Naganohara Station (長野原駅) but changed to the current one in 1991. The current building was also recently constructed in 2013, after the Agatsuma Line was diverted due to the construction of the Yanba Dam.
Kusatsu Onsen (草津温泉)
JR Naganoharakusatsuguchi Station is primarily known as the gateway to Kusatsu Onsen, arguably the most well-known hot spring town in Gunma. Only a short bus ride away from the railway station, the resort is loved by Tokyoites and hot spring lovers everywhere for several reasons, including its charming atmosphere.
Visitors to Kusatsu Onsen will notice the unmistakable smell of sulphur that envelops the whole town. That is due to the town’s highly-prized hot spring water, which is rich in sulphur and minerals that are said to have healing properties. The water is one of the reasons that Kusatsu Onsen is a highly popular tourist attraction that has attracted numerous visitors.
The centrepiece of Kusatsu Onsen is Yubatake (湯畑), the main outlet of the town’s hot spring water. The hot spring water originates from Mount Shirane (白根山), and it flows to Yubatake before it is distributed to the different hotels and hot spring inns in the town. It is the iconic landmark of Kusatsu Onsen, and it has attracted visitors for generations.
Upon reaching the outlet, visitors will also notice several wooden pipes lined across Yubatake. The pipes help to cool down the hot spring water before they are transported to different parts of the town, since the water would be too hot for use when sourced directly from the mountain.
Here’s a tip for those visiting Kusatsu Onsen: catch the view of the town at night. When night falls, Yubatake and the whole town will be beautifully illuminated, transforming into a visual spectacle. It is a breathtaking sight that visitors, as well as those spending the night at any of the nearby hotels and hot spring inns, would not want to miss.
If there is one activity that visitors should catch at Kusatsu Onsen, it is the yumomi (湯もみ), an ancient practice of manually beating the hot spring water with wooden paddles. This helps to cool down the hot spring water to comfortable bathing temperatures without diluting its mineral content, and it’s exciting to watch people flailing wooden paddles with vigour.
To catch this performance, you can drop by the Netsunoyu (熱乃湯) building next to Yubatake, where it is held several times a day. Be sure to come early to grab the best spots in the hall to view it!
Netsunoyu (熱乃湯)
Address: 414 Kusatsu, Kusatsu-machi, Agatsuma-gun, Gunma 377-1711
Access: 2-minute walk from Kusatsu Onsen’s Yubatake
Kusatsu Onsen (草津温泉)
Address: Kusatsu-machi, Agatsuma-gun, Gunma
Access: 25-minute bus ride by *JR Kanto from JR Naganoharakusatsuguchi Station
(*Note: The bus service is covered by JR EAST Passes.)
⑤ JR Manza-Kazawaguchi Station (JR万座・鹿沢口駅)
Finally, we have the JR Manza-Kazawaguchi Station, a railway station just before the line’s terminus at JR Ōmae Station. First opened in 1971, the station is unattended and only has one platform. From this quiet railway station, you can make your way to a hot spring town located high up the mountains.
Manza Onsen (万座温泉)
Less than an hour’s bus ride away from JR Manza-Kazawaguchi Station is Manza Onsen, a hot spring resort town located high up the slopes of Mount Shirane. With an altitude of approximately 1,800m, it is one of the highest-altitude hot spring resorts in Japan, with many of the hot spring hotels and inns offering breathtaking, sweeping views of the surrounding mountains.
Manza Onsen’s hot spring water is sourced from Mount Shirane, and is characterised by its milky-white appearance and high sulphur content, which is said to improve metabolism and blood circulation. What’s more, the town’s hot spring hotels and inns offer amazing hot spring baths with this water, so visitors staying here can enjoy all of its health benefits.
There’s also something special about Manza Onsen that makes it different from other hot spring towns near the Agatsuma Line: snow activities! Manza Onsen is also popular as a snow resort, and from mid-December to late March, the town turns into a winter wonderland where visitors can take part in skiing and snowboarding along the slopes of Mount Shirane.
Manza Onsen (万座温泉)
Address: Hoshimata, Tsumagoi-mura, Agatsuma-gun, Gunma
Access: 45-minute bus ride by *Manza Highway (万座ハイウェーバス) from JR Manza-Kazawaguchi Station
(*Note: The bus service is not covered by JR East Passes.)
Closing
The Agatsuma Line is a unique train line that allows visitors to access some of Gunma’s best hot spring towns with ease. Plus, with a train service such as the Limited Express Kusatsu plying on the train line, those based in Tokyo can conveniently make their way to these hot spring towns directly from the city.
Isn’t it exciting to see a single train line that enables you to visit so many hot spring towns? Why not explore the line for yourself, and take part in a “hot spring hopping” experience to enjoy the best hot springs that Gunma has to offer? I certainly think I will make wonderful memories if I travel on this line, and I bet you will too!
JR TOKYO Wide Pass
If you want to explore the Agatsuma Line and other parts of Gunma, consider the JR TOKYO Wide Pass, an affordable pass that offers unlimited rail travel on JR East lines (including bullet trains) in the valid area for 3 consecutive days at only ¥15,000. You can also make seat reservations for bullet trains, some limited express trains and Joyful Trains online for free, up to 1 month in advance, on the JR-EAST Train Reservation.
Header image credit: ググっとぐんま写真館 (left), ©JNTO (right), illustAC
