Discover Slate Country

The epic ruins of North Wales’ once-great slate industry are now a Unesco World Heritage Site. Julie Brominicks marvels at the spectacle

- By Julie Brominicks. Photographs by Getty, Alamy, Mary Evans and Laura Hallett

It is a wow moment. The walk here was impressive, with its views to Eryri (Snowdonia) summits – but now that I am peering into Moel Tryfan Quarry, I am stunned.

It is the colours that are beautifully shocking. The detergent-blue reservoir lying in a crushed ring of purple slate is encircled by green-gold grass and snow-powdered peaks roaring up to a bruised sky. I have walked here before – I remember being saluted by a passing scrambler-bike rider, and swirling cloud revealing waste tips and walls. I already knew the quarry had drama but I had not before seen its true colours.

Now cloud dissolves the hues, leaving only a memory – and slate waste underfoot that clatters or shatters, fragile yet resilient. There are slate pockets across north-west Wales, but particularly in three large diagonal veins. This Cambrian-Age purple-blue slate running through Llanberis is the oldest (up to 541 million years), while the other two – one running through Blaenau Ffestiniog and the other through Corris – are Ordovician Age (up to 485 million years) and grey. All were worked throughout the Industrial Age to meet a global and domestic demand for roofing slates that some 400 quarries tried to meet – most unsuccessfully, owing to the usual cycle of boom and bust.

The landscape tells the story, with its quarries and mines. (Generally, mining refers to underground extraction and quarrying to over-ground.) It is also told, largely in Welsh, by chapels, terraced houses and communities.