|Date||25 February 2012|
|Location||Cwm Eigiau, Carneddau||SH 70133 63594; 53.15358°N, 3.94353°W|
The tramway linking the nearby Cedryn Quarry to the river Conwy at Dolgarrog was extended to Cwm Eigiau Quarry in about 1863. From 1874 to 1885 the quarry was operated by the Caedryn and Cwm Eigiau Slate Company, which since 1863 had been the Caedryn Slate Quarry Company. The venture was ultimately unsuccessful owing to the poor quality of the slate.
The slate mill was powered by waterwheel and the remains of a wall carrying water to the wheel and of the wheel pit can still be seen.
Some of the quarrymen would have lodged in the barracks at the quarry complex; others would have walked to work from Bethesda – a hike of at least six miles up and over a 900-metre-high col in the Carneddau mountains.