Tsurushi Silver Mine

Tsurushi Silver Mine

Photo by Hoichi Nishiyama

This silver mine led to the discovery of
the Aikawa Gold and Silver Mine

The Tsurushi Silver Mine is a mine site located approximately 1.2 km south of the Aikawa Gold and Silver Mine. Mining continued from 1542 to 1946.

In 1589, when Uesugi Kagekatsu of Echigo province invaded and took rule of Sado, he placed a local magistrate at the Tsurushi Silver Mine to direct its management. Uesugi’s rule over Sado led to a large-scale development of the mine.

Mining began at the Tsurushi Silver Mine in the middle of the 16th century with “surface mining,” where ores were mined on the surface of the ground. This was followed by “tunnel mining” by mine proprietors from the Iwami Silver Mine, which enabled simultaneous exploitation of multiple veins and drainage inside the tunnels, resulting in a dramatic increase in the amount of silver produced.

In addition, due to the division of labor such as mining, ore-dressing, and smelting, the efficiency of the operation improved, which attracted many mine workers from various parts of the country in search of silver. A town for the mine workers and Sawane, the port for bringing in supplies, were developed, and Tsurushi entered a period of prosperity called Tsurushi sengen (meaning “one thousand houses in the Tsurushi area”).

The discovery and development of the Tsurushi Silver Mine significantly impacted the development of mines on the island, which led to the discovery of a large gold and silver vein in Aikawa. After the discovery of the Aikawa Gold and Silver Mine, the center of the gold and silver mines of Sado gradually shifted to Aikawa. When the Local Magistrate’s Office (Magistrate’s Residence) in Tsurushi, the base of mine management, was moved to Aikawa in 1603, the mine workers themselves also gradually moved to Aikawa.

Hyakumaidaira Mining Zone, a large surface mining site

Hyakumaidaira Mining Zone, a large surface mining site

The mining area is said to have been developed in the initial days of the Tsurushi Silver Mine, with a concentration of large surface mining sites where ores were mined on the surface of the ground. It is said that Hyakumaidaira (“100-mai Flatland”: mai was a unit used to measure the production of gold and silver before the 17th century) got its name from the 100 mai of silver paid as tax every month. (National Historic Site)

Byobusawa Mining Zone, chase mining site

Byobusawa Mining Zone, chase mining site

In the Byobusawa mining zone, relics of “chase mining,” where mining was performed by following the shape of the exposed veins along the stream, are well preserved. (National Historic Site)

Otaki-mabu Tunnel(Photo by Hoichi Nishiyama)

Otaki-mabu Tunnel

This is one of the examples of tunnel mining typical of the Tsurushi Silver Mine, which appears in records and pictorial maps from the Edo period (1603–1868). Robotic investigation of the tunnel has revealed that the tunnels are preserved in almost the same condition as they appear in the Edo period pictorial maps. (National Historic Site)

Local Magistrate’s Office Site

Local Magistrate’s Office Site

At the end of the 16th century, Uesugi Kagekatsu established a local magistrate’s office here to control the gold and silver mines of Sado. By 1603, when the Tokugawa Shogunate established the Sado Magistrate’s Office in Aikawa, the local magistrate’s office had become the center of the mine management on Sado. The remains of the office building, ore dressing plant, and furnace are found in the area where the local magistrate’s office was located. (National Historic Site)

Tsurushi Aramachi District (Photo by Takashi Amano)

Tsurushi Aramachi District

The settlement of the Tsurushi Silver Mine was formed around the site of the Local Magistrate’s Office, where ore-dressing and smelting operations were carried out. The site shows how the residential district gradually expanded to accommodate the rapidly growing population accompanying the prosperity of the silver mine. This is evident from the irregularly shaped terraces which were randomly connected and the absence of main streets within the settlement. (National Historic Site)

Three Mining Methods

Surface mining

This is a method in which veins containing gold and silver that appear on the mountain’s surface are dug along with the sediment. Many of the mines are crater-shaped.

▲ Hyakumaidaira, a large surface mining site (Tsurushi Silver Mine)

Chase mining

This is a method of mining by irregularly following veins that appear on the ground’s surface.

▲ Byobusawa Mining Zone (Tsurushi Silver Mine)
Sometimes there would be an accumulation of rainwater in the surface and chase mining sites.
Therefore, a more efficient method of digging was introduced.

Tunnel mining

This method involves examining beforehand where the veins are located and digging a tunnel from the side of the mountain to reach the veins underground. This method was more efficient since two or more veins could be dug simultaneously. In addition, digging from the side eliminated concerns about rainwater.

At the Tsurushi Silver Mine, 556 surface mining sites, four chase mining sites, and 108 tunnel mining sites remain in good condition.

Otaki-mabu Tunnel (Tsurushi Silver Mine) Photo by Hoichi Nishiyama