Ashio Copper Mine is located
about 20 km southwest of central Nikko city and about 10 km south of
It is in the upstream valley of Watarase River, and the river flows through Kiryu city on Gunma Prefecture located about 30 km southwest of Ashio.
This mine was found in 1610, and until the middle of 19th century, it
had produced copper in large quantities.
The copper had been used to build Nikko Toshogu shrine and Edo Castle, or to make coins.
The mine had declined temporarily, but promising mineral veins were
found in 1888, then this mine became active situation again.
In the early 20th century, this was the largenst mine in Japan, so the population was increased to the second largest number after Utsunomiya in Tochigi Prefecture.
But from then, pollution by this mine began to appear.
Mineral poison gas had killed trees, then the mountains around this mine became bald.
Mudslides had often occured, and muds had flown down the stream, then floods had been caused.
However, the government and the prefecture had been unable to pinpoint
the exact cause.
These questions were left unanswered, but the mine had declined in changes of the times.
At last, this mine was closed in 1973.
Today, this mine has been designated as a national historic site.
On the mountains, forests are covering.
We can tour the driftway by tram, and visit a few museums about this mine.
All photoes by Railstation.net
Cedar Avenue of Nikko
Tobu World Square
Ashio Copper mine