Graig Ddu quarry is a disused slate quarry near Blaenau Ffestiniog, in Gwynedd, North Wales. Although output was only about 3,000 tons a year, it reputedly has 36 saw tables and the same number of dressing machines on site. As with others in the area, the quarry suffered from a lack of water, resulting in the siting of the mill some distance away, at a lower level.

Cwm Prysor Viaduct, which is occasionally referred to as Blaen-y-Cwm Viaduct, is a railway viaduct which crosses the Afon Prysor in thinly populated uplands east of Trawsfynydd, Gwynedd, Wales. It was built by the Bala and Festiniog Railway. It carried a single track on a line that ran between Bala Junction and Blaenau Ffestiniog. The line it was built for went out of service in 1961.