Visited this site in May 2017 as a pleasant detour from Tokyo (and using some private railway line not subject to the wonderful Japan Rail Pass).

The cost was 1,000 yen entrance + 200 yen audioguide and 200 yen conservation viewing desk.

The mill was completed in 1872 after local government decided to import mechanized Western technologies of silk processing. Technical advisers from France were invited, while trainees were hired from local female workers. Other factories using Tomioka mill model were constructed around the country afterwards. Introduction of mass production technologies led to modernization of Japanese economy.

The mill have been producing raw silk till 1987 when all the reeling machines were preserved in the original state.

In overall I liked the whole cluster of buildings, which are interesting mix of colonial style constructions and Japanese traditional design features. Many industrial architectural innovations already known in Europe were first introduced in Japan in this mill.

I was lucky to visit on Sunday, when there are various workshops and exhibitions involving demonstrations of how the silk was gathered from the cocoons, very interesting process.

The funniest fact about the mill: young female Japanese workers were reluctant to work at the mill, because there were rumours that the French were drinking ... blood!!! All this was because the locals saw French drinking wine, something they never saw before.

For me the site deserves its status due to unique combination of industrial cooperation at its very beginning, good preservation level and outstanding example of vertically integrated production of silk.