Japan’s largest gold and silver mine, in operation since the end of the 16th century
The Aikawa Gold and Silver Mine was the largest gold producer in Japan from the end of the 16th century to the end of the 20th century. From the Edo period (1603–1868) to the middle of the Meiji period (1868–1912), the mine was managed by the national government. All the gold produced was used as currency to support national finances over a long period of time. Although the mine was mechanized and large-scale production began during the Meiji period, the mining sites of olden times remain intact, along with many properties representing the area’s long history of gold production technology.
Edo Period
The Aikawa Gold and Silver Mine is said to have been discovered by mine proprietors from the Tsurushi Silver Mine, who ventured into the mountains of Aikawa seeking new veins. This was Japan’s largest gold and silver mine, where approximately 40 tons of gold and 1,800 tons of silver were mined during the Edo period (1603–1868). As gold and silver mining in Aikawa began, many people came from outside the island. The population of Aikawa, which had only a dozen houses by the seaside, is said to have grown to 50,000 at one time.
At first, people gathered in Kami-Aikawa near the mines, where a town was established, and soon, towns such as Kyo-machi, Komeya-machi, and Misoya-machi were built in a planned manner according to their residents’ occupation around the Sado Magistrate’s Office, which was built at the tip of a plateau facing the sea. As the population grew rapidly, daily necessities, such as rice, wood, and clothing, were brought in from all over the country. Meanwhile, the production of goods for mines flourished on Sado Island. Furthermore, by using technology for tunnel mining and surveying, new rice paddies were developed on marine terraces and in mountainous regions throughout the island.
Some of the gold mined at the Aikawa Gold and Silver Mine and placer gold from Nishimikawa was processed into koban coins at Aikawa and transported along with the silver to Edo from Ogi Port. The shogunate used this gold and silver as political funds and for foreign trade. However, in the latter half of the 17th century, good-quality ore gradually dwindled, and with tunnels becoming deeper, it became difficult to drain the water that gushed out into the tunnels, resulting in a significant decline in the production of gold and silver. The introduction of new technology was required to revive the mines. Although mines were regained by digging drainage tunnels and improving drainage tools, no new veins were discovered after the latter half of the 18th century, and the mines gradually declined.
Doyu-no-warito Opencut Site（Photo by Hoichi Nishiyama）
Doyu-no-warito Opencut Site
The surface mining site at the top—the symbol of the Aikawa Gold and Silver Mine—was dug by human hands in the Edo period and is 74 m deep and 30 m wide. The large hole at the bottom is a mining site from after the Meiji period where dynamite was used. (National Historic Site/National Important Cultural Landscape)
Sado no kuni kanahori no maki (Picture of gold production in Sado),
collection of Aikawa Folk Museum
Sado Gold and Silver Mine Picture Scrolls
Sado is the only mine in Japan that conducted operations from mining through to minting koban coins. More than 100 picture scrolls depicting the operation processes of the mines still remain in Japan and abroad. These scrolls allow us to trace the history of mining technology and mining management in detail.
Sado magistrates who contributed to the development of gold and silver mines
The number of magistrates dispatched by the shogunate reached 102 during the Edo period. Here we introduce the magistrates who made significant contributions to the development of the Sado Gold and Silver Mines.
Okubo Nagayasu
Served as magistrate from 1603-1613
Okubo Nagayasu was appointed as Sado’s Magistrate by Tokugawa Ieyasu in 1603. In addition to Sado, he served as the magistrate of Kai, Iwami, and Izu. He incorporated the technology and management method of the Iwami Silver Mine at the Sado Gold and Silver Mines and established the magistrate’s office in Aikawa, carried out systematic town development, built roads to mines, and developed ports. The production of gold and silver in Sado was greater than it had ever been until this point, and Aikawa became very prosperous.
Built by Okubo Nagayasu in 1603, this was the center of mining management and administration in Sado. In 2000, the site was reconstructed to its original state, as it was during the 1850s. (National Historic Site/National Important Cultural Landscape)
This was a mining town built on a plateau by Okubo Nagayasu. Along the street connecting the gold and silver mines and the magistrate’s office, buildings from different periods are lined up that tell the history of the mines, such as townhouses in the Edo period and company houses of mine workers in modern times. (National Important Cultural Landscape)
This mining settlement came into being with the development of the Aikawa Gold and Silver Mine in the Azuchi-Momoyama period (1568-1600/late 16th century), which was developed into the mining town of Aikawa. In the early Edo period, the settlement prospered so much that it was called Kami Aikawa sengen (meaning “one thousand houses in the Kami-Aikawa District”), and it is believed that there were 22 to 23 towns in the district. (National Historic Site/National Important Cultural Landscape)
Ogihara Shigehide
Served as magistrate from 1690-1712
In the latter half of the 17th century, the sites of exploitation gradually went deeper underground, and underground water in the tunnels started posing a problem. Ogihara Shigehide, who served as Sado’s magistrate at the time, excavated drainage tunnels to drain the underground water that had accumulated in the tunnels into the sea.
It took nearly five years to complete the 1.1 km-long Minamizawa Drainage Tunnel by manually digging through the underground bedrock. With the completion of this drainage tunnel, gold and silver production increased again.
Minamizawa Drainage Tunnel Site
Approximately 1 km to the sea was dug with mining chisels and hammers over five years from 1691. Even today, underground water inside the tunnel continues to be drained into the Sea of Japan.
(National Historic Site/National Important Cultural Landscape)
Ishigaya Kiyomasa
Served as magistrate from 1756-1759
Ishigaya Kiyomasa submitted opinions to the shogunate regarding the exemption of annual tributes, the development of industry, and the magistrate’s office organization, bringing about significant reforms. In addition, he assembled refiners working in various parts of the town at the magistrate’s office, and established a yoseseriba (ore-dressing plant) to improve work efficiency.
