Penrhyn Slate Quarries, near Bangor, Wales, c 1842.
© Science Museum / Science & Society Picture Library
Lithograph made and published by Newman & Co of London, showing a monumental open cast mining landscape. Slate has been mined here since the 16th century and is still used as a roofing material. At the start of the 21st century this slate quarry was still the largest in the world and being used.