Snowdonia National Park, Gwynedd, Wales, UK. 17th February, 2015. A gable wall and fireplaces are seen at the abandoned Rhosydd Slate Quarry. Rhosydd Slate Quarries began in 1840 and employed 200 men at its peak in the 1880s when over 6,000 tons of saleable slate a year was produced. The quarrying continued until the 1950s but never really recovered after the ‘Great Fall’ in 1900, a catastrophe which destroyed a large part of the most profitable reserves. Credit: Graham M. Lawrence/Alamy Live News.