Tomioka Silk Mill

Tomioka Silk Mill was once a major silk production factory; today it is a historic site and a UNESCO World Heritage Site. The mill was established by the Japanese government in 1872. Advanced Western machinery and technology were imported, foreign specialists were invited, and it soon became an important centre of silk production in Japan. It played a significant role in Japan’s rise as an influential silk-producing nation. Japan eventually became the world’s leading exporter of raw silk, and the silk industry emerged as a central pillar of the country’s modernisation. The industry also contributed greatly to the development of railroad construction, as it became necessary to connect silk-producing regions with the ports from which the silk was exported.

Tomioka Silk Mill also played an important historical role in changing the position of women in society, helping establish them as a vital part of Japan’s industrial workforce. Many Japanese women were trained at Tomioka Silk Mill, where they learned new skills and technologies. After returning to their home regions, they often became leading professionals in their local silk industries. Throughout the mill’s 115 years of operation, women played a central role in sustaining its production.

The mill’s buildings still reflect their historic importance and the progressive spirit of the time. Constructed with red bricks — a material unusual in Japan at that time — they symbolise modernisation, industrialisation, and Westernisation during the Meiji era.

Tomioka Silk Mill: Overview of Its Cultural Heritage

Tomioka Silk Mill preserves more than one hundred historic structures that illustrate Japan’s early modernisation and the development of mechanised silk production. Three major buildings — the Silk-Reeling Mill, East Cocoon Warehouse, and West Cocoon Warehouse — are designated National Treasures.

Key National Treasure Buildings

West Cocoon Warehouse

Built alongside the East Cocoon Warehouse at the time of the mill’s founding, it underwent a major conservation project completed in 2020. The first floor now includes a glass-walled space supported by seismic-reinforcement frames, used for exhibitions and a multipurpose hall that hosts various events.

East Cocoon Warehouse

A 104-meter brick-and-timber structure that stored dried cocoons on the second floor and housed offices and workspaces on the first. Its arched entrance bears the inscription “Meiji 5” (1872). The building contains the Tomioka Silk Gallery and a shop.

Silk-Reeling Mill

A 140-meter factory where cocoon filaments were processed into raw silk. At its establishment, 300 French metal reeling basins were installed, forming one of the world’s largest mechanized silk-reeling facilities. A truss roof system provided a large column-free interior.

History and Designation

After operations ceased in 1987, the site was designated a National Historic Site in 2005 and several structures became Important Cultural Properties in 2006. In 2014, three buildings received National Treasure status. Tomioka City manages the site today. Many early buildings were constructed using mokukotsu-renga-zō, a hybrid method combining wooden framing with brick walls, influenced by French industrial architecture. Materials such as brick, timber, and stone were locally sourced, and French bonding techniques were used in the brickwork.

Other Historic Structures

Important Cultural Properties include the residences of French technicians and instructors, the steam engine house, an iron water reservoir built in 1875, and the original drainage system, which still functions for rainwater discharge.

Demonstrations and Exhibits

The site offers demonstrations of restored French-style reeling machines, steam-powered Brunat engines, and a year-round silkworm biology display. A hands-on workshop allows visitors to reel silk from cocoons by hand.

Tomioka Silk Gallery

Located in the East Cocoon Warehouse, the gallery exhibits locally produced cocoons, raw silk, and woven works made with Japanese and French techniques. A sales area features a range of silk products made from 100% Tomioka-grown cocoons.