This mine was once the most productive in Japan, producing gold, silver, and copper for the Tokugawa shogunate. After closing in the late 1980s, it has been preserved as a historical museum. Part of the mine's 325 km (250 miles) of underground tunnels, some running as deep as 1,969 feet, are open to the public. Down in the depths, robots illustrate how Edo-period slaves worked in the mine and the appalling conditions they endured. The mine is a tough 40-minute uphill walk or a five-minute taxi ride (about ¥900) from the bus stop at Aikawa. Three daily Nana-Ura Kaigan buses let you off at the Sado-Kinzan-mae bus stop.
1305 Shimo-Aikawa, Sado-shi, Niigata-ken, 952-1501, Japan