According to Ministry of the Environment statistics, Gunma (Kanto) has 98 onsen areas and 459 hot-spring sources. This page lists 62 onsen in Gunma with their water types. The most common water type among them is Chloride Spring (18 onsen).
Source: Ministry of the Environment, FY2024 Hot Spring Utilization Survey (as of March 31, 2025). Best-known onsen = most annual Wikipedia views.
| Water Type | Count | Share |
|---|---|---|
| Chloride Spring | 18 | 29% |
| Unknown | 13 | 21% |
| Simple Thermal Spring | 9 | 15% |
| Sulfate Spring | 7 | 11% |
| Bicarbonate Spring | 5 | 8% |
| Sulfur Spring | 4 | 6% |
| Other | 4 | 6% |
| Carbon Dioxide Spring | 1 | 2% |
| Iron Spring | 1 | 2% |
| Facility | Water Type |
|---|---|
| Usui Pass Forest Park Exchange Hall 'Toge no Yu' | Chloride Spring Sodium – bicarbonate/chloride spring |
| Hana no Eki Katashina Hanasaki no Yu | Simple Thermal Spring Alkaline simple spring |
| Takayama Onsen Fureai Plaza | Unknown |
| Takayama Onsen | Unknown |
| Otaki no Yu A day-use bathing facility representative of Kusatsu Onsen, known for its 'awase-yu' method of gradually acclimating bathers to the hot water temperature. | Sulfur Spring Acidic sulfur spring |
| Sainokawara Open-Air Bath A vast open-air bath within Sainokawara Park. | Chloride Spring Acidic – chloride/sulfate spring |
| Manza Onsen Nisshinkan A long-established inn with three bathing areas and milky-white water, welling up at 1,800 m with one of the highest sulfur concentrations in Japan. | Sulfur Spring Acidic, sulfur-bearing magnesium/sodium – sulfate spring |
| Name | What kind of onsen |
|---|---|
| Manza Onsen Details | At 1,800m elevation, tied with Nigorigo Onsen for the highest-altitude hot spring resort in Japan. Strongly acidic sulfur springs discharge 5.4 million liters a day from 27 sources. Also known as a ski resort in winter, though parts of the prefectural and national roads leading up to it close under snow each winter. |
| Kirizumi Onsen Details | A secluded lodge, Kinyukan, in a remote valley within Joshin'etsu-kogen National Park, said to have been visited by historical figures such as Katsu Kaishu and Ito Hirobumi. |
| Hoshi Onsen Details | Chojukan, the sole inn standing at 800m in Joshin'etsu-kogen National Park, famous for its mixed-bathing bath where spring water wells up directly through a floor of river stones — a hot spring dating to the Meiji era. |
| Onsen Town | Summary |
|---|---|
| Kusatsu Onsen Literature | The folk song Kusatsu-bushi, sung while working the hot spring water (yumomi), contains the well-known line following 'Kusatsu yoi toko, ichido wa oide' (Kusatsu, a fine place — come at least once): 'Even a doctor, even Kusatsu's waters, cannot cure the sickness of love.' Details |
| Kusatsu Onsen Legends & Origins | Legend holds that Yamato Takeru, returning from a campaign to subdue the eastern provinces, saw hot steam rising from a valley and bathed in the spring; the stone he is said to have sat on is called 'Goza-ishi.' However, no contemporary historical record mentions Kusatsu Onsen, and the story is regarded strictly as a later-era legend. Details |
| Yujuku Onsen Travelogue | Said to be the setting of one of Tsuge Yoshiharu's best-known works, Gensenkan Shujin (The Master of Gensenkan, 1968). It also appears in his essay collection Tsuge Yoshiharu no Onsen (Tsuge Yoshiharu's Hot Springs); the town serves as a gateway to Mikuni Pass in Minakami and is said to have a 1,200-year history. Details |
| Ikaho Onsen Legends & Origins | After his defeat at the Battle of Nagashino in 1575, Takeda Katsuyori ordered his retainer Sanada Masayuki to develop Ikaho Onsen as a place for wounded soldiers to recuperate. By the following year, 1576, hot-spring water was piped from its source and distributed evenly to houses along a stone stairway through sixteen outlets (komagata) on either side — said to be Japan's first example of hot-spring town planning. That stairway became the origin of today's Ishidan-gai (stone steps street), which is also said to have doubled as a defensive stronghold against the Uesugi and Hōjō clans. Details |
| Shima Onsen National Health Resort | Shima Onsen is said to have been discovered around the year 989, and by the Meiji era it was thriving as a toji (hot-spring cure) resort. In 1954, it became one of Japan's first three National Health Resort Onsen, designated alongside Sukayu Onsen and Nikko-Yumoto Onsen. According to the area's plan document as revised in 2024, 38 of its 42 hot-spring sources remain in use today, and its sodium–calcium chloride–sulfate waters still underpin the town's toji atmosphere. Details |
| Shima Onsen Travelogue | An old hot spring said to have been discovered around 989 and designated a National Health Resort Hot Spring. Rustic single inns still remain in Oku-Shima, and it is included in the Kanto/Koshin chapter of Tsuge Yoshiharu no Onsen. Details |
| Shiriyaki Onsen Travelogue | A chloride spring known for its unusual open-air bath, where the bed of the Nagasasa River itself is the hot spring. The open bath, simply partitioned off from the riverbed, is featured in the Kanto/Koshin chapter of Tsuge Yoshiharu no Onsen. Details |