Overview:Deep in the mountains of Tochigi Prefecture, 100 kilometers north of Tokyo, Ashio has long been known as a mining town. Copper deposits were first discovered there 400 years ago and mining continued there until the 1970's. In its heyday, the mine produced 40 percent of all of Japan's copper and nearly 40,000 people lived in the area. Although mining brought prosperity, it also created massive pollution: Ashio became infamous as the site of the country's first major pollution disaster. Sulfur dioxide gas from the refining process killed off the surrounding forests. And huge amounts of toxic chemicals were carried downstream to the lowlands by the Watarase River. On this episode of Journeys in Japan, potter Euan Craig travels to Ashio to see for himself how people have brought life back to the mountains, thanks to a massive reforestation program.