Penrhyn Slate Quarries, Wales, 1842.
© Science Museum / Science & Society Picture Library
Hand-coloured lithograph by W Crane of Chester showing of 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. Published by T Humphreys of Bangor, Wales.