Omori Ginzan Important Preservation District for Groups of Traditional Buildings is a historic townscape stretching through Omori Town in Oda City, Shimane Prefecture. The area developed as the central settlement of Iwami Ginzan, once one of the world’s major silver mines.
Located beside the silver mine, Omori became an important administrative and economic center during the Edo period (1603–1868), when Iwami Ginzan and the surrounding territory were placed under the direct control of the Tokugawa shogunate. Today, the town still retains many traces of its former prosperity.
In 1987, the area was designated as a national Important Preservation District for Groups of Traditional Buildings in recognition of its outstanding historic landscape. Samurai residences, merchant houses, temples, shrines, and the former government office site remain harmoniously integrated with the everyday lives of local residents.
The historic townscape extends for approximately 2.8 kilometers along a narrow valley. With red-tiled roofs, stone walls, waterways, and white-plastered buildings lining the streets, walking through Omori can feel like stepping into the atmosphere of an Edo-period Japanese town.
Iwami Ginzan is traditionally said to have been discovered around the 14th century. From the 16th century into the early 17th century, it became one of the world’s leading sources of silver. Silver from the mine was distributed throughout Japan and also exported overseas, contributing to Japan’s economy and international trade.
Omori played a vital role in supporting the mine. During the Edo period, the area came under direct shogunate control, and a magistrate’s office was established here. Omori developed into the political and economic center for more than 150 villages associated with the Iwami Ginzan territory.
Many people connected with the mine lived in the town, including miners, merchants, samurai, craftsmen, and government officials. Their activities shaped the distinctive townscape that can still be seen today.
The street layout and town planning of the Edo period have survived in many places. The arrangement of buildings, historic roads, and waterways provides a tangible sense of how the community once functioned at the height of the silver mine’s prosperity.
Stone is one of the most noticeable features of Omori’s historic landscape. The area around Iwami Ginzan was shaped by volcanic activity and is rich in stone materials such as green tuff.
These stones were skillfully used for retaining walls, building foundations, waterways, and other structures. Their extensive use gives the town a solid, distinctive appearance. Remains of former stone quarries can also be found in the area, showing that stone processing was once an important local activity.
Another fascinating feature is the continued use of kaname-ishi, stones once used in the silver refining process. Some remain in private gardens and around entrances, where they are naturally reused as stepping stones or stands for bonsai. This is a particularly vivid example of how the history of Iwami Ginzan has become part of everyday life.
As you walk through Omori, small waterways flowing beside the streets are easy to notice. Clear spring water from the surrounding mountains runs through the town, creating a gentle sound that adds to the peaceful atmosphere.
The waterways were constructed by cutting through bedrock and making clever use of the natural terrain. They demonstrate the ingenuity of the people who lived here centuries ago and continue to contribute to both the town’s landscape and daily life.
The reddish-brown roofs of Sekishu tiles are another defining feature of Omori. Produced from locally available clay in the Iwami region, Sekishu tiles are known for their durability and distinctive warm color.
Looking across the town, visitors can often see red tiles on merchant houses, while gray smoked tiles were more commonly used on samurai residences and administrative buildings. This difference reflects the function and status of individual buildings.
At sunset, the red tiles catch the soft evening light and create an especially beautiful scene, making this a memorable time for a leisurely walk and photography.
The Imodaikan Museum stands on the site of the former Edo-period magistrate’s office and introduces visitors to the history and daily life of Iwami Ginzan.
The museum building itself was constructed in 1902 as the former Nima County Government Office and is also valued as an example of modern-era architecture.
Inside, visitors can see mining tools, minerals, historical documents, and other materials that illustrate the lives of the people who supported the silver mine. Exhibits about Ido Heizaemon, a magistrate popularly known as the “Potato Magistrate,” are also particularly notable.
Ido Heizaemon is remembered locally for policies that helped people suffering from famine, and his name remains respected in the region.
Kumagai Family Residence was the home of a wealthy merchant who played an important role in the economy of Iwami Ginzan. The residence is designated as an Important Cultural Property of Japan.
The extensive complex retains its main house and storehouses, allowing visitors to experience the lifestyle of prosperous merchants during the Edo period. Features such as underground storage rooms, ingenious storage spaces, and seasonal shitsurai, or traditional interior arrangements, provide an insight into Japanese domestic culture.
In summer, reed screens and bamboo blinds were used to keep interiors cool, while winter brought furnishings such as thick carpets and hand warmers. These details reveal how people adapted their homes to the changing seasons.
The Former Kawashima Residence was the home of a lower-ranking official who worked for the local magistrate’s office. It offers an opportunity to learn about the lifestyle of samurai and the traditional culture of storage and household organization.
One of its distinctive features is a storage space known as a tsushi second floor, an ingenious way of making effective use of limited space. Displays of armor and traditional weapons also provide a glimpse into samurai culture.
At Rakanji Temple, visitors can see a remarkable collection of Five Hundred Rakan statues created to pray for the souls of people who died while working at the silver mine and to honor ancestors.
The stone statues were carved over a period of more than 20 years, and each has a different facial expression. A local saying holds that visitors can always find a statue resembling someone they wish to see again.
The temple grounds also feature a Money-Washing Benzaiten, believed to bring good fortune in financial matters. Visitors can also experience the traditional practice of passing through a narrow passage known as tainai-kuguri, which has a symbolic connection with spiritual purification.
Numerous former mine tunnels, known as mabu, remain around Iwami Ginzan. At sites such as Shingiri Mabu and Fukujinyama Mabu, visitors can see actual excavated tunnels and gain an appreciation for the mining technology used in the past.
It is said that miners could advance through the hard rock by only about 30 centimeters per day. Marks left by hand excavation can still be seen on the rock walls, offering a direct connection with the difficult work of the miners.
The tunnels also reveal efforts to prevent cave-ins and the painstaking process of following narrow veins of silver ore. Exploring these remains helps visitors understand the scale of the challenges faced by the people who worked at the mine.
At Jojo Shrine, visitors can observe carefully constructed stone walls made from precisely shaped stones fitted closely together. These structures demonstrate the high level of stoneworking skills developed in the region.
Saishoji Temple preserves examples of kote-e, a distinctive decorative plastering technique that flourished in the Iwami region. Sculptural designs of phoenixes, flowers, and other motifs were created using plaster, demonstrating the remarkable skill of local plaster craftsmen.
Omori is not simply an open-air museum or tourist attraction. It remains a living community where residents continue their everyday lives among historic buildings and streets.
In recent years, traditional houses have been adapted into cafes, shops, galleries, and other contemporary spaces. This has created a natural meeting point between traditional culture and modern life.
One representative example is Gungendo, where visitors can enjoy dishes made with local ingredients as well as regional crafts and lifestyle products.
When exploring Omori, visitors are encouraged to respect the privacy and daily lives of local residents. Walking quietly through the streets allows you to appreciate the rare atmosphere of a place where history and contemporary community life continue side by side.
The Omori Ginzan Important Preservation District for Groups of Traditional Buildings preserves far more than the history of a silver mine. It offers a glimpse into traditional Japanese town planning, architecture, craftsmanship, and everyday life.
Red Sekishu tile roofs, quiet waterways, substantial stone walls, historic residences, temples, and shrines come together to create a landscape shaped by centuries of human activity.
Every street and small detail can reveal something new, making Omori a place that rewards slow exploration. Rather than simply passing through on the way to the mine ruins, take time to walk through the historic district and experience the atmosphere of a town where the legacy of Iwami Ginzan remains part of everyday life.
From JR Oda-shi Station, take a bus for approximately 20 minutes and get off at the Omori Daikansho-ato bus stop.
The historic preservation district is best explored on foot at a leisurely pace. Walking allows visitors to appreciate the traditional architecture, waterways, stonework, and small details that might otherwise be missed.