Ynys-y-Pandy Slate Mill

Lovely couple of hours cycling into the hills above Porthmadog. Epic scenery. Amazing slate mill. Back via the beach at Criccieth.

Ynysypandy slate-slab mill, and its surrounding yard, rail-access and water-supply system, was built to serve Gorsedda quarry in 1856-7 by the local contractor Evan Jones of Garndolbenmaen, probably to the design of the distinguished engineer James Brunlees. It is ingeniously planned so that the natural fall of the site assisted the manufacturing process. An internal pit accommodated an overshot water wheel, supplied by the Henwy stream, and on the south side a long curving ramp brought branches of the railway from Gorsedda quarry into the mill at two different levels, serving the middle and upper floors. The grand, round-headed openings are closely spaced like a Roman aqueduct, and derive from foundry practice. The eastern gable is surmounted by a decorative feature incorporating a false chimney stack, and the windows were at one time framed. It is one of very few architecturally ambitious buildings in the slate industry of Wales.
The mill specialised in the production of slate slabs for floors, dairies, troughs, urinals, etc. In its heyday, in 1860, it was producing over 2,000 tons per annum, but seven years later production was down to 25 tons per annum (due to the poor quality of the quarried slate) and the business went into liquidation in 1871.  
The building provided a venue for eisteddfodau until the roof was removed around 1906. It was conserved by the Snowdonia National Park in 1981 and is accessible to visitors.


Climbed the Wall of Prenteg to get there. Great fun!