Situated in the center of Nagano prefecture, Okaya-shi lies to the west of Lake Suwa-ko and is surrounded by mountains. From the Meiji (1868 - 1912), Taisho (1912 - 1926), and early Showa (1926 - 1989) periods, the abundant natural water helped Okaya flourish as a silk manufacturing town. At the time, Nagano prefecture was Japan's number one producer of silk. Most of the production was concentrated in Okaya and the vicinity of Suwa, enough to earn the international nickname of "Silk Okaya." Large businesses as well as unions of small businesses began to get involved in sales and expanding distribution to other prefectures. Schools were soon being built with the aid of silk manufacturers, and many other fields such as Okaya's non-silk businesses, transportation system, communication system, and culture were being affected by the silk industry. Machinery, equipment, records, and research reports of the time are now on display at the Okaya Silk Museum. The homes that belonged to silk business owners such as the Hayashi family still exist today. The residences reflect the industrial prosperity of the golden era and are maintained as some of Japan's important cultural assets.