Mount Akagi is the collective name for a vast mountainous area in northeastern Gunma Prefecture. It is a magnificent volcano whose highest peak is Mount Kurobisan. Rather than referring to a single mountain, the name Mount Akagi encompasses a group of peaks surrounding a volcanic caldera.
Along with Mount Haruna and Mount Myogi, Mount Akagi is one of the “Three Mountains of Jomo”, the mountains most closely associated with Gunma Prefecture. It has also been selected as one of Japan’s 100 Famous Mountains, 100 Scenic Views, 100 Famous Mountains of the Kanto Region, and New 100 Flower Mountains. Its rich natural environment and beautiful scenery attract hikers and visitors throughout the year.
The summit area includes Lake Onuma, a caldera lake; Lake Konuma, a volcanic crater lake; and Kakumanbuchi Wetland. Depending on the season, visitors can enjoy boating, fishing, camping, hiking, and other outdoor activities.
Mount Akagi is a large composite volcano consisting of a central caldera surrounded by mountains ranging from approximately 1,200 to 1,800 meters in elevation. Extensive highland plateaus extend around the lower slopes to elevations of about 800 meters, while the mountain’s broad foothills span approximately 25 kilometers in diameter.
At the center of the peaks forming the outer rim are Lake Onuma, Lake Konuma, and Kakumanbuchi Wetland. These distinctive landforms, created by volcanic activity, give Mount Akagi its expansive and varied landscape.
Mount Kurobisan (1,828 m) is the highest peak of Mount Akagi. Other major peaks include Mount Komagatake, Mount Jizodake, Mount Choshichirosan, Mount Nabewari, Mount Arayama, and Mount Suzugatake. Each offers different landscapes and hiking experiences.
Lake Onuma is the largest caldera lake in the summit area of Mount Akagi and serves as one of the main centers of tourism on the mountain. Akagi Shrine stands on its shore, while various spots around the lake provide opportunities for walking and enjoying the scenery.
Visitors can enjoy boating and lakeside walks at Lake Onuma, as well as fishing and camping depending on the season. In winter, the lake sometimes freezes over, making it possible to enjoy seasonal activities such as smelt fishing on the frozen lake.
Lake Konuma, meanwhile, is one of Mount Akagi’s volcanic crater lakes. It has a quieter atmosphere than Lake Onuma and offers beautiful scenery surrounded by the mountain’s natural environment.
Kakumanbuchi Wetland is a wetland near the summit of Mount Akagi with a circumference of approximately 500 meters. Its distinctive scenery has earned it the nickname “Little Oze”, referring to the famous Oze wetlands, and it is one of Mount Akagi’s representative natural attractions.
A wooden boardwalk allows visitors to walk through the area while enjoying the surrounding scenery. Various alpine and wetland plants can be seen depending on the season, making this a peaceful place to experience Mount Akagi’s natural environment at close range.
One of Mount Akagi’s attractions is the dramatic change in scenery throughout the year.
In spring, flowers such as Japanese azaleas and Japanese azaleas known as renge-tsutsuji add color to the mountain. After the snow melts, the fresh landscape provides excellent conditions for spring hiking.
Summer at Mount Akagi is cooler than the lowlands, with refreshing highland breezes and lush greenery. The area is popular as a summer retreat and is well suited to hiking and lakeside walks.
In autumn, the mountains are transformed by red and golden foliage. The combination of colorful forests, lakes, and mountain scenery creates one of Mount Akagi’s most memorable seasonal landscapes.
In winter, snow and ice cover the mountains, creating an atmospheric winter landscape. At Lake Onuma, visitors can enjoy activities such as smelt fishing, while skiing and snow hiking are available in the surrounding area.
Mount Akagi offers a variety of hiking and mountain-climbing trails suitable for different levels of experience, from beginners to intermediate hikers. The ability to choose a route according to fitness level, interests, and available time is one of the mountain’s attractions.
This is one of the most popular mountain routes on Mount Akagi. Starting near the shore of Lake Onuma, the trail climbs toward the ridgeline and continues to Mount Komagatake and Mount Kurobisan. From around the summits, hikers can enjoy expansive views toward the Kanto Plain.
The climb from Lake Onuma to Mount Kurobisan generally takes around 1.5 hours, while the descent from Mount Komagatake to Lake Onuma takes roughly one hour. Actual times vary according to trail conditions, weather, and individual fitness, so hikers should allow sufficient time for their journey.
This route starts from the parking area at Shirakaba Farm on the western side of Lake Onuma and heads toward Mount Suzugatake via Mount Kuwagarayama. The climb to the summit takes approximately one hour. The trail ends at the summit, so hikers return by the same route.
Other hiking options include routes around Mount Nabewari and Mount Arayama, as well as trails connecting Mount Choshichirosan and Ko-Jizodake. Visitors can select a route according to their hiking experience, fitness level, and the season.
Many areas of Mount Akagi are located above 1,400 meters, meaning temperatures are lower than in the surrounding lowlands and weather can change quickly. Hikers should bring appropriate warm clothing, rain gear, and sturdy hiking shoes suited to the season and trail conditions, and should always prioritize safety.
From the summits and ridgelines of Mount Akagi, visitors can look across the surrounding mountains and the Kanto Plain. As one of the Three Mountains of Jomo, Mount Akagi offers expansive mountain scenery characteristic of Gunma’s landscape. On clear days, the views extend far into the distance.
The mountain area is home to a wide variety of plants and animals. While hiking and walking, visitors can also observe seasonal flowers, vegetation, and wild birds in their natural environment.
The area surrounding Mount Akagi features numerous attractions and facilities where visitors can enjoy nature. In addition to boating and lakeside walks at Lake Onuma and nature observation at Kakumanbuchi, highlights include the Akagi Park Visitor Center, Akagi Onsenkyo hot spring area, Shirakaba Farm, and ski resorts.
After hiking or exploring the mountain, visitors can relax in the hot spring waters of Akagi Onsenkyo and unwind after a day outdoors.
National Route 353 running along the southern foothills of Mount Akagi is known as the “Akagi Kaze Line.” Hot springs, farms, flower-viewing spots, soba restaurants, and other attractions can be found along the route, making it an enjoyable driving route for discovering the natural and cultural attractions of the area.
Exploring beyond the summit area to the foothills allows visitors to combine mountain scenery with hot springs, local food, and seasonal flowers for a broader experience of Mount Akagi.
Mount Akagi has long been revered as a site of mountain worship. Approximately 300 Akagi Shrines are distributed throughout the Kanto region, reflecting the widespread influence of the religious tradition associated with the mountain.
Within the Mount Akagi area are Daido Akagi Shrine, located on Kotorigashima Island in Lake Onuma, and Miyosawa Akagi Shrine in Miyosawa. Both shrines have strong connections with the worship of Mount Akagi.
Daido Akagi Shrine is particularly distinctive, with its vermilion buildings standing on Kotorigashima, a small peninsula extending into Lake Onuma. The shrine, lake, and surrounding mountains combine to create an impressive landscape.
In the past, people living around the mountain are said to have climbed Mount Akagi for various purposes, including prayer, religious training, and rituals to comfort the spirits of the deceased. Today, Akagi Shrine is also known as a shrine where women’s wishes are believed to come true, attracting many visitors.
Mount Akagi was formerly known as “Kuroho,” a name that also appears in the ancient Japanese poetry anthology Man’yoshu. Several theories exist regarding the origin of the present name “Akagi,” including theories relating to the reddish appearance of the mountain, mountain worship and mythology, and Buddhist terminology.
The mountain’s name is pronounced both “Akagiyama” and “Akagisan.” Locally, “Akagiyama” is more commonly used, reflecting the mountain’s close connection with everyday life in Gunma.
Mount Akagi also appears in “Jomo Karuta,” a popular local card game featuring Gunma’s history, culture, and landmarks. Its famous phrase, “Akagi’s long foothills,” reflects the mountain’s broad and imposing presence and its importance as a symbol of Gunma.
Mount Akagi is believed to have begun its volcanic activity approximately 500,000 years ago, gradually developing its present landscape over a long period. Its geological history is generally understood to include several stages, including the formation of an older stratovolcano, a younger stratovolcano, and the central volcanic cones.
During this long history, large eruptions, collapses of the volcanic body, and caldera formation occurred. These processes created the distinctive landforms seen today, including Lake Onuma, Lake Konuma, and Kakumanbuchi. Mount Akagi is therefore not only a scenic tourist destination but also an important place for observing landforms created by volcanic activity.
Mount Akagi has a long history and is associated with various legends and traditions connected to mountain worship. Among the best known are the legend of a battle with Mount Nantai in Nikko and stories associated with the famous local outlaw Kunisada Chuji.
At Senjogahara, located on the northwestern foothills of Mount Nantai in Nikko, a legend tells of a battle between the deity of Mount Nantai and the deity of Mount Akagi. According to the story, the deity of Mount Nantai won the battle and the deity of Mount Akagi was defeated.
This legend is connected with local beliefs and place names around Mount Akagi and remains an intriguing part of the mountain’s cultural history.
Mount Akagi is also widely associated with Kunisada Chuji, a famous outlaw figure from the Joso region. Stories about Chuji became popular through traditional storytelling and New Kageki theater from the Meiji period through the early Showa period.
The phrase “Even tonight, the mountain of Akagi”, associated with these stories, became widely known and helped establish the name of Mount Akagi in popular culture throughout Japan.
Mount Akagi is closely connected not only with the natural landscape but also with the climate and daily life of Gunma. The cold northerly wind that blows down from Mount Akagi toward the Kanto Plain in winter is known as “Akagi Oroshi.” It is one of the seasonal winds most strongly associated with Gunma Prefecture.
The mountain’s appearance in Jomo Karuta further reflects how familiar and symbolic Mount Akagi is to the people of Gunma.
Mount Akagi can be reached by route bus from Maebashi Station or by car. Some roads leading toward the summit area are closed during winter.
From winter through early spring, snow and icy road surfaces can affect travel conditions. Visitors should prepare equipment appropriate for the season and weather and check the latest road and transportation information before setting out.
Mount Akagi is a vast mountainous area where visitors can experience magnificent volcanic landscapes, rich forests, lakes, wetlands, seasonal flowers, and colorful autumn foliage. In addition to hiking and mountain climbing, visitors can enjoy recreation at Lake Onuma, walks around Kakumanbuchi, hot springs, and scenic drives.
The mountain also has a rich cultural heritage, including centuries-old mountain worship, Akagi Shrines, references in the Man’yoshu, numerous legends, and cultural traditions such as Jomo Karuta and the seasonal Akagi Oroshi wind.
From spring flowers and refreshing summer highlands to autumn foliage and snow-covered winter landscapes, Mount Akagi offers a different experience in every season. As one of Gunma’s most representative mountains, it is a destination where visitors can take their time discovering both its magnificent natural environment and its long cultural history.
Take the Kanetsu Kotsu Bus from the No. 6 bus stop at the North Exit Bus Terminal of JR Maebashi Station to the Akagisan Visitor Center bus stop (approx. 70 min.).
(Weekdays) “To Fujimi Onsen” → Transfer at <Fujimi Onsen> to “Akagisan Visitor Center”.
(Sat., Sun., Holiday) “To Akagisan Visitor Center” Akagisan direct bus
＜Kan-etsu Expressway
From Akagi IC to the summit area Onuma, about 40 minutes (about 25 km)
From Maebashi IC to the summit area Onuma is about 60 minutes (about 31 km).
＜Kita Kanto Expressway
From Isesaki IC to the summit area Onuma is about 60 minutes (about 38 km).