Small underground working with adits through to Oakeley from platform on cliff.**

Two adits remain open today: the upper adit is stoped out to the surface (bank), while the lower adit opens onto a steep stone platform. Near the upper adit are small buildings, rock-cut steps, and a possible smithy. The stone section of the incline remains prominent, and the adjacent cutting and boltholes mark the former timber section. Evidence of on-site sawing is visible in the form of circular-sawn slate ends, and historical accounts mention a boiler being lowered from the site in the early 20th century. At Glan y Pwll, some reused buildings may be linked to the quarry operations. The tunnel connection to Oakeley remains accessible and open.

Established around 1860. The initial adit was driven from a natural ledge in the cliff, with a second adit later cut approximately 30 feet below, accessed via a rock-cut platform. Material was lowered by an incline—partly timber and partly stone—to a siding on the Ffestiniog Railway at Glan y Pwll. The quarry likely used the Nant Ystradau mill (SH677433), which had been vacated by Mathews. After a lease dispute, the quarry was absorbed by the Oakeley Quarry, with a connecting tunnel constructed between the two.