Less than 90 years after the mine was opened, the tunnel had reached below sea level, so the 'Sodayu Mine' had to be constantly drained, and it was a continuous battle with water.

Drainage work was done using a wooden machine called a water wheel.

A view of the mining site. Tools called a chisel and a mallet were used to dig through the hard bedrock. The mining work was carried out by engineers called kanahori carpenters, who were in the front line of gold production.

State of Kengiriaratame. Where the tunnel is being inspected to see if it has been dug according to the specifications ordered and how far it has been dug. The headwear was a safety cap made of tightly woven paper called tehen, which was only permitted to those in managerial positions.

The Doyu Mine Course was opened to the public in 2008 with the basic concept of preserving the state of the Sado Mine, which played a central role in the modernization of Japan after the Meiji Restoration, as an industrial heritage site.

Large-scale mining of Doyu no Warito was carried out in the early Edo period in the upper part and in the Meiji, Taisho, and Showa periods in the lower part. The hollow part seen in the photo is also a mining site, but there was a tunnel directly below this hollow, and the ore was transported outside from the Doyu mine by truck.

The mining site forms a nearly vertical precipice, and this type of open-pit mining is unique in the world.

Doyu no Warito is a nationally designated historic site that symbolizes the Sado Gold Mine. "Doyumyaku" was one of the first veins discovered in the Aikawa gold and silver mine in 1601, and mining continued from the Edo period to the upper part and from the Meiji period to the first year of the Heisei period.