Cwm Erch Copper Mine thought to have been in operation mid to late C19th. In fact There is evidence for the operation of Cwm Erch copper mine from 1841 to 1865. A water wheel was erected in 1841. The mine was run by H. McKellar who formed the 'Hafod y Llan Copper and Lead Mines Company' in 1851.
The mine constructions included a tramway, ore platform, upper and lower mills, dressing floor and other buildings and machinery. The remains are reasonably well preserved. Various features survive in an interesting state of preservation. The site consists of a lower ore processing mill (possibly never used), a central mill site where a considerable amount of machinery survives, including the water wheel frame (part of which has been moved and is lying flat on the ground) and the upper terrace or main adit level. This terrace is connected to the central mill site by a chute. On the hillside above are various worked lodes and slots of considerable depth, some with the remains of timber braces and staging. There is also a roofless but otherwise well preserved typical hafod structure with its roof slates neatly stacked nearby.
The whole site is approached from the valley below by way of a graded track. The site is a Scheduled Ancient Monument.

John Latham RCAHMW 25 October 2016.