Water Landscape at the Confluence of the Tone and Watarase Rivers
In the easternmost corner of Gunma Prefecture, where the great Tone River meets its largest tributary, the Watarase, lies a low-lying landscape unlike any other in the Kanto region. Local people have long called this area the "mizuba"—literally, "the water place." For centuries, families here have lived with frequent flooding, treating the rivers not as enemies but as partners. The clever inventions, agricultural methods, and architectural responses born of this relationship are still visible today across the rice fields, embankments, and traditional homesteads of Itakura Town. In September 2011, this remarkable working landscape was selected as an Important Cultural Landscape by the national government—the very first such designation in the entire Kanto region.
A Land Shaped by Water
Itakura Town sits at the southeastern tip of Gunma, on a quiet plain where the Tone and Watarase rivers once met before Edo-period engineering rerouted their channels. The Tone is the largest river in Japan by drainage area, and the Watarase is its biggest tributary, so the land caught between them was inevitably a place of standing water, marshes, and seasonal floods. Archaeological evidence shows people have lived here since the Jomon period, but it was only from the late medieval era onward—roughly four hundred years ago—that large-scale settlement and farming became possible, thanks to the construction of dikes and the deliberate redirection of river channels.
Older residents did not call the floods "disasters." They used the word "oomizu," meaning simply "the big water." Floods could destroy a harvest, but they also delivered fresh, nutrient-rich silt that made the next year's crops abundant. This balanced view—seeing water as both a threat and a gift—is the philosophical foundation of the entire landscape.
Why It Was Designated as an Important Cultural Landscape
Japan's Important Cultural Landscape system, established under the revised Cultural Properties Protection Law, recognizes places where human activity and the natural environment have shaped each other into something distinctive and irreplaceable. The selection of Itakura's water landscape in 2011 honored a singular truth: nowhere else in Japan does such a complete, well-preserved record of life at a major river confluence remain. The designated area covers portions of three districts—Ebise, Shimogoka, and Itakura—where the visible landscape still tells the full story of how a community learned, over centuries, to coexist with great rivers.
What makes the place exceptional is not any single feature but the layering of them. Encircling embankments built in the late medieval and early modern periods still curve through the fields. The water-control system that took shape from the seventeenth through the nineteenth centuries—and was completed during Japan's modernization—still functions today. Rice paddies follow ancient contours, traditional homesteads still keep their flood-defense structures, and protective groves of native trees still mark the corners of family compounds. Together, these elements form a continuous, working cultural landscape that the national government recognized as having genuine national value.
Highlights of the Landscape
Mizuka — Refuge Buildings on Earthen Mounds
The most striking element of the local architecture is the mizuka, a small storehouse or refuge building raised on an earthen mound at one corner of a family compound. When floodwaters rose, families could climb to the mizuka with their valuables, their stored grain, and—if needed—their lives. Many mizuka still stand throughout Itakura, built of plastered earthen walls or sturdy timber, and each one is a testament to a household's careful planning across generations.
Agebune — The Hanging Boats
Look closely at the eaves of older farmhouses in the area, and you may see a long, narrow flat-bottomed boat suspended from the rafters. This is an agebune, a flood-evacuation boat kept always ready overhead so that, when the water came, a family could lower it directly into the rising flood and row to safety. The agebune is one of the most evocative symbols of the mizuba way of life, and visitors today can experience riding one along the Yatagawa River as part of a local cultural tourism program.
Kawada — The Lifted Paddy Fields
In the wettest zones near rivers and marshes, farmers developed an ingenious agricultural method called kawada. Workers would dig long ditches into the wetland, pile the excavated earth onto the surrounding ground, and create slightly raised paddy beds where rice could grow above the waterline. The ditches doubled as drainage channels and as waterways for small boats. This technique made cultivation possible on land that would otherwise have been useless—turning a flood-prone marsh into a productive grain-belt.
Yanagiyama — The Willow Groves
Along the levees and damp edges, communities planted and managed groves of willow known as yanagiyama. The fast-growing willow provided a steady supply of firewood and material for tools, while its dense roots helped stabilize riverbanks against erosion. The yanagiyama is a quiet but essential part of the landscape, marking the boundary between cultivated fields and the rivers themselves.
Yashiki-rin — The Homestead Forest
On the northwest corner of nearly every traditional homestead, you will find a small, dense grove of native trees—usually Japanese hackberry, muku-no-ki, and bamboo. These yashiki-rin act as windbreaks against the cold winter winds that sweep across the plain, but they also serve as a flood defense, as their dense root systems and pliable trunks help break the force of fast-moving water. The choice of species reflects a deep practical knowledge of which trees thrive in a flood-prone environment.
Kakoizutsumi and Numayoke-zutsumi — The Old Embankments
Two kinds of historic earthworks still trace the edges of the rice-growing zones. The kakoizutsumi, or "encircling embankment," wraps around clusters of fields and farmsteads to keep floodwater out, while the numayoke-zutsumi, or "swamp-blocking embankment," holds back water from the marshes that once dominated the plain. These mounds are not engineered concrete walls but living earthworks, often blanketed in grass and trees, and they have been part of the working landscape for four hundred years.
Visiting the Mizuba
The most practical access point is Itakura Toyo-Daimae Station on the Tobu Nikko Line, which can be reached directly from central Tokyo in roughly one hour. From the station, the broad rice plains, the embankments, and the homesteads with their distinctive groves are all within reach by bicycle, taxi, or short bus ride. The town offers a rental cycle service, and the flat terrain makes cycling an ideal way to see the landscape at the human scale at which it was built.
One of the most memorable ways to engage with the water culture is the agebune ride along the Yatagawa River. Operated as a cultural-tourism experience by the town, the trip uses traditional flat-bottomed boats poled by a single boatman with a long bamboo pole, gliding for about two kilometers through quiet waters lined with willows and reeds. The program began as an educational activity in 2001 and was so well received that it became an annual offering the following year. Reservations are usually required in advance.
Spring and early summer—April through June—offer green rice fields, blossoming wisteria, and the most active wildlife. Autumn brings ripening rice and migratory birds. Winter is cold but clear, with views across the great open plain. Visitors are encouraged to follow local guidance: the embankments and rural lanes are working agricultural infrastructure, and the homesteads are private property, so quiet, respectful observation is essential.
Surrounding Attractions
Itakura is rich in complementary attractions that round out a day or weekend trip.
Itakura Raiden Shrine
Just a short distance from the heart of the cultural landscape stands Itakura Raiden Shrine, regarded as the head shrine of the many Raiden ("thunder god") shrines scattered across the Kanto region. Its origins are traced by tradition to Prince Shotoku in the late sixth century, and the present main hall, completed in 1835, features remarkable carvings by master craftsmen of the period. The auxiliary Hachiman-Inari shrine within the grounds is the oldest surviving wooden building in Gunma Prefecture and is designated as a nationally Important Cultural Property.
Watarase Retarding Basin
Just to the north lies the Watarase Yusuichi, a vast 3,300-hectare retarding basin that spans four prefectures and serves both flood control and drinking-water supply functions for the Tokyo region. In 2012 it was registered as a Ramsar Convention Wetland of International Importance. Its enormous reed beds, grasslands, and the heart-shaped Yanaka Lake at its southern end attract birdwatchers, cyclists, and nature lovers year-round.
The Three-Prefecture Border
An unusual cultural curiosity sits at the eastern edge of town: a small, simple marker where Gunma, Tochigi, and Saitama Prefectures meet at a single point. While more than forty such tri-prefectural points exist in Japan, this is reportedly the only one located on flat, walkable ground rather than on a mountain ridge or stream. Visitors can step around all three prefectures in a few seconds.
River-Fish Cuisine
Centuries of fishing in the local waters have produced a distinctive culinary tradition. Catfish (namazu), eel, carp, and crucian carp are the local specialties, and a handful of long-established restaurants near Raiden Shrine have been serving them for well over a hundred years. Catfish tempura, with its surprisingly delicate white flesh, is the most famous dish and a must-try for visitors curious about the foodways of a watery land.
- 📍 Plan Your Visit to Gunma
- Find tours, activities & transport passes near Waterscape of the Tone River and Watarase River Confluence
- [ Kusatsu Onsen & Tomioka Silk Mill Heritage Tours ]
Q&A
- What exactly is an "Important Cultural Landscape"?
- It is a category of nationally protected cultural property recognizing places where the natural environment and the daily lives or livelihoods of local people have together shaped a distinctive and significant landscape. Selection is made by the Minister of Education, Culture, Sports, Science and Technology under the Cultural Properties Protection Law. Itakura's water landscape was the first such designation in the Kanto region.
- Can ordinary visitors actually see the historical features described here?
- Yes. Many mizuka, the homestead groves, the kakoizutsumi embankments, and traditional rice paddies are visible from public roads and embankment paths. Some agebune are still hung under farmhouse eaves and can be glimpsed from the lanes. Please remember that the homesteads themselves are private homes, so observation should be from public ways.
- How do I get there from Tokyo?
- Take the Tobu Skytree Line from Asakusa or the Tobu Nikko Line and disembark at Itakura Toyo-Daimae Station. The trip takes about one hour from central Tokyo. By car, the Tateyama Interchange or Sano-Fujioka Interchange of the Tohoku Expressway both offer access in about twenty minutes from the highway.
- Is the agebune boat ride suitable for international visitors?
- The agebune experience is a relaxed, scenic ride and does not require any prior knowledge of Japanese to enjoy. The boatman handles all the operation. Booking ahead through the local tourism office is recommended, and asking your accommodation or a Japan-based travel service to assist with reservations is the easiest path.
- When is the best season to visit?
- Late April through early June offers freshly planted rice paddies that mirror the sky, and the Raiden Shrine festival takes place at the start of May. Autumn, from late September into November, brings golden rice and clear views. Winter is cold and quiet, but the bare landscape reveals embankment lines and earthworks that are otherwise hidden by vegetation.
Basic Information
| Designation Name | Water Landscape at the Confluence of the Tone and Watarase Rivers (利根川・渡良瀬川合流域の水場景観) |
|---|---|
| Category | Important Cultural Landscape (national designation) |
| Date of Selection | September 2011 (first designation in the Kanto region) |
| Location | Parts of Ebise, Shimogoka, and Itakura districts, Itakura Town, Ora District, Gunma Prefecture |
| Key Elements | Mizuka (refuge buildings), agebune (flood-evacuation boats), kawada (raised paddy fields), yanagiyama (willow groves), kakoizutsumi and numayoke-zutsumi (historic embankments), yashiki-rin (homestead windbreaks) |
| Nearest Station | Itakura Toyo-Daimae Station, Tobu Nikko Line (about one hour from central Tokyo) |
| Tourism Inquiries | Itakura Town Office, Industrial Promotion Division (Tel: 0276-82-1111) |
References
- 利根川・渡良瀬川合流域の水場景観 - Itakura Town Official Website
- https://www.town.itakura.gunma.jp/cont/s021000/d021010/miryoku_mizubakeikan.htm
- 重要文化的景観 利根川・渡良瀬川合流域の水場景観 - Itakura Town
- https://www.town.itakura.gunma.jp/cont/s026000/d026010/20121212152754.html
- 利根川・渡良瀬川合流域の水場景観 - Cultural Heritage Online (Bunka.nii.ac.jp)
- https://bunka.nii.ac.jp/heritages/detail/225812
- 利根川・渡良瀬川合流域の水場景観 - National Council of Cultural Landscape Districts
- https://www.bunkeikyo.jp/landscape/landscape-254
- Itakura Raiden Shrine - Itakura Town Official Website
- https://www.town.itakura.gunma.jp/cont/s021000/d021010/raiden_kankou.htm
- Watarase Retarding Basin (Ramsar Wetland) - Itakura Town
- https://www.town.itakura.gunma.jp/cont/s021000/map/443shisetsu.html
- Important Cultural Landscape - Wikipedia (Japanese)
- https://ja.wikipedia.org/wiki/%E9%87%8D%E8%A6%81%E6%96%87%E5%8C%96%E7%9A%84%E6%99%AF%E8%A6%B3
Last verified: 2026.04.29