Hey Guys,


This is very much a report of two halves, but of the same place. The first part features my solo and un-permitted archaeological visit to the above ground part, tracing the remains of the engine house and worker’s village above ground.

Secondly I have included a few underground shots from a later trip, organised by Miles Moulding as part of a Go Below, underground adventures visit. Thanks again to Miles for a great trip and a good five hours underground, the quarry is sealed tight and only possible to access escorted. For further info on these trips then please visit his website.


This quarry and the one at Blaen y Cwm differed from all other Welsh slate quarries in one key aspect. The slate was first quarried underground before being transported up an incline, as opposed to down. This was facilitated by a large winding house situated at the bottom of the incline, where wagons of finished slate would be hauled up the incline before being loaded onto the Rhiwbach Tramway which wound its way around the side of the valley to Blaenau Ffestiniog. The large engine house also powered the quarry machinery and underground inclines.

The quarry began on site in the early 19th century, but the pit workings didn’t begin in the 1860s. The underground workings are vast to say the least, featuring 8 levels and a 1:100 adit starting 350ft below the surface and exiting near Penmachno. Before the steam winding engine was built, slate was taken from the adit entrance via horse via Cwm Penmachno to the quay at Trefriw. The Rhiwbach Tramway opened in 1863 and revolutionised how slate was moved out of the quarry.
This quarry was one of the most remote in all of North Wales, and was frequently cut off for long periods. As a result the workers established living quarters around the quarry which at its peak was almost a village in status. The worker’s village feature a shop, a school, family accommodation and single men’s barracks.

Despite its large size the quarry’s output rarely exceeded 6000 tons and was subject to many temporary closures which lasted for long periods. Electricity finally arrived in 1934, however the quarry was finally closed 17 years later in 1951.

1 - View from top of incline





6 - The rubbish heap of rejected slate



9 - The incline towards Penmachno

The Worker's Village

Underground - Organised Trip