Drws-y-coed is believed to have been worked since medieval times and it is known that there were rich copper workings in the area at the time of Edward I in 1284 (source: Nantlle Valley History Society). The mine is marked as disused on the first edition Ordnance Survey 25 inch map of 1889 although it is known to have been worked by Simdde Dylluan until 1911 under lease to a German firm (source: AIA). The remains include various buildings, levels and several wheelpits. The site was powered by leats from Llyn y Dywarchen, a natural lake.
Source:
David Gwyn & Merfyn Williams (1996) `A Guide to the Industrial Archaeology of North West Wales?. Association for Industrial Archaeology