Extensive mill area. Short adit to pit with remains of dressing shed. Deep adit, which may be open to bottom of pit. (Visited Jul 2025, confirmed no sign of adit in pit)

Clogwyn y Gwin Slate Company Ltd registered in 1879, dissolved < 1916

During 1880s, a short upper tunnel brought slate to and extensive dressing area. An incline then took finished product down to a sidings on the NWNGR.

During the 1920s, slates were dressed in a small dressing shed within the pit. Finished slate then taken via the bottom adit and a short aerial ropeway to the railway.

Take the path from Rhyd Ddu towards Glanrafon. After the path crosses the railway, a slatey path climbs up on the right towards the quarry.