Maenofferen Slate Mine - Blaenau Ffestiniog

The size of this place shouldn't be underestimated, there are at least seven working levels accessible, with the rest submerged underwater. You could spend an entire day here and still only scratch the surface of what it has to offer.

After parking down the road, we headed up the steep, unforgiving landscape where signs of surface workings were clearly visible. It’s best to visit on a weekend to avoid the workers, but from what I’ve seen, they generally don’t seem to mind. The 'Go Below' lot drove past in a bus full of people and gave us a questioning stare before continuing over the hill.

The cutting sheds were the first stop along the way, with some saws, cutting tables, and slate slabs still left from when it was last worked in the ’90s. It seems to be a popular spot for wild camping, offering decent shelter from the elements.

Heading through a short tunnel brings you out at the winch housing above the main incline. Just thinking about the walk down that steep incline makes my legs ache. Since slate is notoriously slippery when wet, a crabwalk seems like the safest way to approach it.

I’ve visited this place numerous times over the years and find it a great spot for a casual wander or to take someone new underground. It’s hard to get lost thanks to the grid formation the levels were worked. The hardest part is finding the good stuff.

If someone asked me where the ‘best bits’ were, I’d struggle to point them out on a survey. I usually just stumble across them. But for me, the main attractions would be the EIMCO rock shoveler, testing boreholes, the fans, and the shorter stemple-filled inclines.

History

“Maenofferen Slate Mine located in Blaenau Ffestiniog is a prominent site within the Slate Landscape of Northwest Wales UNESCO World Heritage Site, reflecting the region’s rich industrial heritage. Slate was first extracted at Maenofferen around 1800, and by 1861 the quarry had been purchased by Sir William Fothergill Cooke and Mr. Veasey, producing an impressive 400 tons of slate that year. The quarry flourished throughout the 19th century, expanding significantly and developing extensive underground workings that pushed further downhill toward the town. By 1897, the quarry employed 429 men, nearly half of whom worked underground. Although it initially lacked a direct connection to the Ffestiniog Railway’s Duffws terminus, slate was shipped via the Rhiwbach Tramway, incurring higher transport costs than some competitors. This challenge was addressed in 1920 when the company constructed a new incline linking its mill to a neighboring quarry, allowing Maenofferen to use their railway connection and significantly reduce shipping costs. The quarry was also known for its early adoption of technology. Around 1900, locomotives began operating on internal tramways, and in 1918 hydro-electric power was introduced. Its twin slate mills, built between 1870 and 1897, were originally water-powered and converted to electric power by 1906 structures now regarded as some of the best-preserved examples of 19th-century slate-processing architecture. After the Second World War, production began to decline, and by the 1970s, Maenofferen was acquired by the Greaves company. Underground production ceased entirely in November 1999, marking the end of large-scale underground slate extraction in North Wales. In the years since, slate has continued to be extracted topside on a limited scale, now under the ownership of a nearby quarry”.