The Akenobe mine was in operation from around the ninth century until its closure in 1987. Copper and tin were its most plentiful ores, and at one point, Akenobe supplied 90 percent% of Japan’s tin. Even today the mine has visible veins of ore, but by the 1980s it proved less expensive to import ore than to mine it.
When the mine closed, it had eighteen levels with a total of 550 kilometers of tunnels. Although its lower tunnels were purposely flooded, the upper part of the mine has been preserved for guided tours.
The mine stays around 11 degrees Celsius year-round, making it ideal for the aging of soy sauce and sake. Sanyohai, a local sake brewery, uses local rice and water to make a special sake called Senzakura, which is then aged in the mine.