The site is a twenty-four kilometre stretch of the lower Derwent Valley, from Matlock Bath to Derby, and unites the historic textile communities of Cromford, Belper, Milford and Darley Abbey. These areas include a large proportion of the earliest examples of mills in the world. Here, innovative development during the late 18th and early 19th centuries harnessed the power of the river and marshalled the workforce to textile manufacturing. Above all, the scale of the mill buildings changed the manufacture of textiles by introducing factory production to the world.
The Derwent Valley site is significant because of the development of early technology at the Silk Mill in Derby in 1721 and Cromford Mill in 1771. Here, factory production was introduced which transformed the scale of the output and the numbers of workers on the site. A shift system was introduced with workers employed in large buildings land living in nearby dependant communities. The spread of the factory system created a new cultural tradition and the venture introduced a degree of social enlightenment and concern for the quality of life.