Graig Ddu quarry

Graig Ddu is a slate quarry near Blaenau Festiniog in North Wales that operated with around 36 saw tables and dressing machines for processing the extracted stone. The site employed dozens of workers over several decades and developed infrastructure to transport finished slate away from the hillside location.

Operations began around 1800 as Manod Quarry and the site took the name Graig Ddu during the 1840s as it expanded into a major production center. The quarry operated until 1946 and was an important employer in the region during the peak era of Welsh slate extraction.

The quarry represents the industrial heritage of Wales, where slate mining shaped local communities and contributed to regional architectural development.

The site sits on a hillside and visitors should wear sturdy footwear suited to uneven ground and steep slopes. Allow time to explore the various work areas and processing stations scattered across the quarry floor.

Workers used ceir gwyllt, custom-built single-rail vehicles with supporting arms, to descend the steep slopes from their work areas to the roads below. These handmade contraptions were an ingenious solution that local workers invented to handle the daily challenge of moving between upper and lower elevations.