Lumsdale Valley is a steep-sided wooded gorge in the Peak District near Matlock, Derbyshire, in England.

[2] The monument consists of a series of historic water-powered mills and other fragile industrial archaeological structures and remains.

The privately owned central gorge area of the monument is only accessible by a permissive footpath, which the Society may close when required.

It was used for bleaching and lead smelting, was later used a corn mill and was then used for grinding white barytes for the paint industry.

Soon after Arkwright's patents expired in 1785, a three-storey water-powered cotton mill was built by Watts, Lowe and Co.

The Smithy is connected to the Lower Bleach Works and is a Grade II listed building.