Shimonita’s 3 Geology Highlights
Rootless Mountains Tell Japan’s Story
1. A Great Shift from Sea to Land That Formed the “Rootless Mountains”
The mountain ridges visible from the town have a rounded, bumpy appearance, reminiscent of shapes seen in folk tales.
The “Rootless Mountains (Klippe),” selected as one of Japan’s Top 100 Geological Sites, are rock masses that originated from the eastern margin of the Asian continent and were uplifted and transported toward the Pacific side.
In this area, there is a wealth of high-quality limestone formed in the ocean, which has been widely utilized.
Additionally, the rocky soil along the mountainsides has been used for konjac cultivation.
The orange area is the strata that have been moved.
Traces of the Great Earth Shift
Slip Surface of the Atogura Klippe
This marks the boundary where the upper rock layers were displaced. You can observe the scouring marks left by the moving rock mass.
Folding at Ōkuwabara
This spot shows how the bedrock was bent and folded by tectonic forces.
Maita Fudō Waterfall
One of the rocks forming the Klippe, a granite-like igneous rock and the oldest in Shimonita, creates this 40-meter waterfall.
Nearby stands a shrine dedicated to Fudō Myōō (Acala), a Buddhist deity.
The Rocks That Form the Base of the Rootless Mountains
Aoiwa Park
A park featuring distinctive green rock pavements formed from ancient submarine volcanic eruptions.
Located at the confluence of the Kabura and Nanmoku Rivers, you can find a wide variety of colorful stones along the riverbanks.
HAKUENKA Plant – Shiraishi Industries
This factory produces calcium carbonate from limestone, which is the fossilized remains of ancient coral reefs.
Note: Limestone is no longer quarried in Shimonita. Only the exterior of the factory is viewable; entry is not permitted.
- Geo
- Aoiwa Park, the seven Rootless Mountains (including Ontake, Mt. Ōkuzure, Mt. Yotsumata, and Mt. Fuji), the Atogura Klippe slip surface, the folding at Ōkuwabara, the reverse fault at Miyamuro, Makita Fudō Waterfall, Okukuriyama Gorge, and the Nakakosaka Iron Mine
- Culture
- Shiraishi Industries’ Hakuenka Plant, konjac fields and traditional stone walls
- Bio
- Rare limestone-adapted plants (such as the goldhair fern and Bukō cherry)
2. An Ancient Volcanic Region That Divides the Pacific and Japan Sea
Mount Arafune, located on the border of Gunma and Nagano Prefectures, is an ancient volcano. Rivers on its eastern side flow toward the Pacific Ocean, while those on the west flow toward the Sea of Japan.
Mount Myogi is also an old volcano, famous for its many unique rock formations such as the Stone Gates and other bizarre shapes. It is designated a national scenic site and is known as one of Japan’s “Three Great Strange Scenic Views.”
The Arafune Wind Cave uses a landform where cool air blows out even in summer. It played a key role in Japan’s silk industry and is recognized as a UNESCO World Cultural Heritage site. Nearby, Kozu Farm, Japan’s oldest Western-style ranch, sits on a vast flatland formed by an ancient landslide.
Mt. Arafune
A remnant of massive past volcanic activity, this mountain is one of Japan’s “200 Famous Mountains” and is a popular destination for hikers.
Mt. Myogi
Together with Mount Akagi and Mount Haruna, Mount Myogi is part of the Jomo Sanzan (Three Famous Mountains of Gunma). Its dramatic rock formations—like the Stone Gates, Cannon Rock, and Candle Rock—offer breathtaking natural beauty.
Arafune Wind Cave – A World Cultural Heritage Site
Cold air still flows from this rocky area, formed by the collapse of hardened magma. From the Meiji era to the early Showa period, it served as one of Japan’s largest silkworm egg storage facilities, supporting the silk industry alongside the Tomioka Silk Mill.
Jii and Baa
Among the jagged peaks, the far right is called “Baa” (Grandma), followed by “Jii” (Grandpa), and to the left, a group of peaks called “Kotatsu” (Heated Table). These unique rocks were shaped over millennia by erosion of volcanic material.
Kozu Farm
Japan’s oldest Western-style ranch. It produces high-quality dairy products using fresh milk from Jersey cows. The daily sight of cows walking in a line across the pastures is truly impressive.
Keikanseki (Comb Stone)
The Official Mineral of Gunma Prefecture (Site of the Nishinomaki Mine)
A rare, arsenic-bearing mineral formed by volcanic activity.
Note: Located on private property. Collection is prohibited, and it is toxic—handle with caution.
Mt. Arafune summit
The summit features a flat stretch roughly 1.2 km long. The area includes a natural wetland with mizunara oak forests and wildflowers such as Primula japonica and Ligularia fischeri.
- Geo
- Mount Arafune, Jii and Baa, Mount Myogi & Stone Gates, Keikanseki
- Culture
- Kozu Farm, Arafune Wind Cave, Hot Springs, Former Mining Sites
- Bio
- Chazubomi Moss, Plants named after Myogi (like Myogi Fern, Myogi Bellflower)
3. A Crossroads of Eastern and Western Culture and Trade
Shimonita Town lies in a valley carved by the Kabura River, which flows east to west. The “Shimonita Road” connected the provinces of Musashi, Joshu, and Shinshu. In the Stone Age, it served as a route for obsidian from Shinshu, and from the early modern period, it transported rice from Shinshu, whetstones from Nanmoku, and Shimonita’s local products like hemp, silk, paper, and limestone. The town’s specialties—Shimonita leeks and konjac—have long been loved by travelers.
Median Tectonic Line
The only visible section of the Median Tectonic Line in the Kanto region
In the town center, the riverbed across from Suwa Shrine exposes the Median Tectonic Line, a major fault that runs across the Japanese archipelago. It is responsible for shaping the valley in which the Kabura River flows.
Motojuku (Old Post Town)
Mayama Hills
The Mayama area features two river terraces. Many prehistoric archaeological sites have been found on the upper terrace, and a mountaintop castle was built here in the Sengoku period. Today, the area is a major production site for Shimonita negi.
Shimonita Hydrangea Park
Located on the terrace slope of the Mayama Hills, this garden is in full bloom from mid-June to early July. During the hydrangea festival, visitors can enjoy panoramic views of the Nishijoshu mountains.
Konjac Starch Factories
Shimonita’s valley topography, once perfect for waterwheel-powered konjac starch production, remains one of Japan’s top konjac processing regions. Even today, konjac bulbs from all over Japan are brought here for processing.
Sukiyaki
A sukiyaki dish made with local specialties such as Shimonita-negi (Shimonita leeks), konjac, and shiitake mushrooms is a popular item on school lunch menus.
Jōshin Dentetsu Shimonita Station
One of the “100 Best Stations in the Kanto Region”
Opened in 1897 to transport local resources, the railway connects Takasaki to Shimonita. The station area still retains a charming retro Showa-era townscape.
Suwa Shrine
With its lavishly decorated main hall, the shrine features detailed carvings on its pillars and beams. The autumn grand festival, dating back to the Tenpō era (1830s–40s), is a lively celebration with parades of mikoshi (portable shrines) and festival floats.
Site of the Shimonita War
During the closing days of the Edo period, Shimonita was the site of a battle between the Mito Loyalists (Tengutō) and the Takasaki Domain. Remains of their camps and graves can still be seen in the town.
- Geo
- Mayama Hills and the Archaeological Route (upper terrace), flatlands between Shimonita and Mayama (lower terrace), Futsū Valley, Hanekoshi Gorge, the Shimonita Formation, Kawai Fault (Median Tectonic Line)
- Culture
- Townscape of Shimonita, Shimonita Station, Suwa Shrine, historic sites of the Shimonita Conflict, konnyaku processing, grave of Dōsai Takahashi, Kosakasaka Pass Road, Onigasawa Bridge, Honjuku post town ruins, Beizan-ji Temple (site of Mayama Higashijō Castle), Hydrangea Garden (terrace cliff utilization)
- Bio
- Negi fields, Abuda Fukujusō Flower Village