Sasaune Gallery, Underground copper mine entrance in Takahashi, Japan.

Sasaune Gallery is a former copper mine adit of the Yoshioka mine in Takahashi, Okayama Prefecture. About 250 meters of the tunnel from the entrance is open to visitors, who walk through it wearing helmets. Inside, marks of rock drills and mine cart tracks remain, and part of the tunnel is used for aging alcoholic beverages.

Copper was discovered at the Yoshioka mine in 807, and the adit was worked until 1972, producing chalcopyrite and pyrrhotite. After the town of Fukiya was designated a national preservation district in 1977, the adit was opened to the public in November 1979.

The gallery takes its name from the Sasaune adit of the Yoshioka copper mine, which produced chalcopyrite and pyrrhotite until its closure in 1972. Part of the tunnel is now used for the long-term ageing of alcoholic drinks, a practice visitors can learn about on site.

The passages are best explored with a guide, as the tunnels are narrow and lighting is limited throughout. Sturdy shoes and a jacket are recommended since the underground air is cool and surfaces can be slippery.

Mining tools and equipment remain at their original workstations in the lower chambers, frozen in time. These details allow visitors to follow the actual day-to-day labor of miners step by step.