Sado Island Gold Mine

The Aikawa Gold and Silver Mine on Sado Island is one of Japan’s most significant mining legacies, with nearly four centuries of continuous operation. Tradition holds that the mine was first opened in 1601 by three prospectors. Two years later, in 1603, the Tokugawa shogunate placed the area under direct government control as tenryō, establishing the Sado Magistrate’s Office. The mine became a key pillar of the shogunate’s financial system, producing gold used to mint koban coins that circulated throughout the Edo period. From the late sixteenth century to the mid-nineteenth century, Sado Island flourished as a major gold-producing region under Tokugawa administration. During Japan’s period of national isolation, technological exchange with countries outside Asia was limited, leading mining practices to evolve independently from European and Western-influenced methods. This isolation resulted in the development of large-scale, long-term gold production systems rooted in traditional craftsmanship.

A major shift occurred in 1869, when the mine became a government-operated enterprise during Japan’s rapid modernization. Western engineers were invited to introduce mechanization and modern mining techniques. In 1889, administration transferred to the Imperial Household Agency, integrating the mine into the Imperial estate. Its role as a model mine contributed to the broader industrial modernization of the Meiji era.

In 1896, the mine was sold to Mitsubishi Joint-Stock Company. Under Mitsubishi management, Aikawa expanded into the largest gold and silver mine in Japan, marking a period of extensive development and unprecedented extraction. The mine is notable for producing gold of exceptional purity — up to 99.54% — and at its peak contributed as much as 10% of global gold production. Its longevity and output illustrate a rare example of a sustained, highly organized traditional mining system operating for more than 250 years.

The Aikawa mining complex was remarkable in scale. The main gold vein extended approximately 3,000 meters east to west, 600 meters north to south, and reached depths of around 800 meters. Over 388 years — from the early Edo period to the end of the Shōwa era — the mine produced an estimated 78 tons of gold and 2,330 tons of silver, establishing Aikawa as Japan’s largest gold and silver mine. The underground network of tunnels, extending roughly 400 kilometers (comparable to the distance from Sado Island to Tokyo), has often been compared to an intricate ant nest, reflecting the complex and layered nature of the mine’s development.

Operations continued until March 1989, when declining resources brought nearly 400 years of mining history to a close.

Tours and Experiences

To explore the mine’s history in more depth, several courses are available, each offering a different way to experience the tunnels, technology, and cultural legacy of Sado Gold Mine.

ISLAND MIRRORGE Course

Located within the historic tunnels of the Sado Gold Mine, the ISLAND MIRRORGE Course uses mixed-reality glasses and projection mapping to create a digitally enhanced underground environment. The attraction combines advanced visual technology with a centuries-old mining site, presenting an immersive XR experience that differs from conventional museum displays. A reservation is required to participate in this course. Reservation (Japanese): here.

Sado Gold Mine Course: Edo and Meiji-Era Mining Sites

The Sado Gold Mine Course covers two major tunnel systems: the Edo-period Sōdayū Tunnel and the Meiji-era Dōyū Tunnel, both nationally designated heritage sites. The course also provides close views of Dōyū-no-Warito, the V-shaped open-cut scar that serves as a symbol of the Sado mines.

Sōdayū Tunnel

Carved in the early 17th century, the Sōdayū Tunnel showcases hand-dug mining at the western end of the Aoban ore vein. Characteristic features of Edo-period extraction remain visible, reflecting early mining techniques overseen by specialized workers.

Dōyū Tunnel

Opened in 1899, the Dōyū Tunnel illustrates the modernization of Sado’s mining industry through mechanized excavation. Original industrial facilities, including trolleys, workshops, and ore-crushing equipment, remain preserved. The course includes multiple viewpoints of Dōyū-no-Warito, highlighting both surface and underground mining conducted from the Edo period through 1989.

Industrial Landscape

Surrounding facilities, such as a 1930s machinery workshop, retain equipment used until the mine’s closure, providing a preserved example of Sado’s modern mining infrastructure.

Guided Yamashi Tour

The Guided Yamashi Tour focuses on the Ōgiriyama Tunnel, a nationally designated historic site completed in 1647. The tour follows hand-dug passages from the early Edo period, preserved almost exactly as they were when first excavated. Visitors move through high-ceilinged entrance areas, parallel tunnels, and ventilation openings that once ensured airflow. Remnants of later industrial use, including trolley rails from the Meiji period onward, are also visible. The scale of the excavation and the quiet mining chambers convey the atmosphere of early mining work, while sections of complete darkness illustrate the conditions faced by miners underground. Reservation (Japanese): here.

Gold-Leaf Application Workshop

The workshop offers two types of gold-leaf activities: decorating a mini Sado koban replica or applying gold leaf to a personal plate. Participation requires a reservation: here.