Grace's Guide is the leading source of historical information on industry and manufacturing in Britain. This web publication contains 138,078 pages of information and 222,858 images on early companies, their products and the people who designed and built them.
Since the 18thC Blaenau Ffestiniog has been the centre of the Welsh slate industry. The industrial revolution created a huge demand for slate roofing and the quarries in Gwynedd employed 16,000 men by the middle of the 19thC.
Oakeley Quarry is a slate mine in the town of Blaenau Ffestiniog, north Wales. 
The area produced roof slates called Duchess and Countess.
Eventually machine cutting a alternative roofing materials caused the collapse of the Welsh slate boom and high unemployment followed.
The Llechwedd Slate Caverns and the Gloddfa Ganol Slate Mine are made safe for tourists and give an accurate account of the history and impact of the area.