Kōshin'etsu

Kōshin'etsu is an area of complex and high rugged mountains—often called the "roof of Japan"—that include the Japanese Alps. It consists of the Yamanashi, Nagano, and Niigata prefectures. The population is chiefly concentrated in six elevated basins connected by narrow valleys. It was long a main silk-producing area, although output declined after World War II. Much of the labor formerly required in silk production was absorbed by the district's diversified manufacturing industry, which included precision instruments, machinery, textiles, food processing, and other light manufacturing.