Pen-y-Bryn Quarry

Overview

A Nantlle Valley slate quarry named for the 17th-century house that stood on the site and remained occupied by residents until after the Second World War, notable for producing distinctive purple and blue slate divided by a thin vein of green, and for the unusually complete survival of its worker housing and processing buildings.

History

Pen-y-Bryn Quarry takes its name from a 17th-century house that stood on the site, and which continued to be lived in throughout the quarry's working life around it, remaining occupied until after the Second World War. The quarry produced distinctive purple and blue slates, divided by a thin vein of green slate running between them. Between 1836 and 1844, Pen-y-Bryn and the neighbouring Cloddfa'r Lon quarry made use of water-wheel technology, connected by rods to a series of pumps to keep the workings clear of water; both quarries later adopted chain inclines, a technology invented locally, to move slate up and down the steep quarry faces. The complex of buildings used by the quarry's workers survives today almost complete, including their cottages, a saw mill and a weighbridge -- an unusually full survival for a Nantlle Valley slate quarry.

Workings

Worked for purple and blue slate divided by a thin green vein; drained between 1836 and 1844 by water-wheel-powered pumps, and later served by locally-invented chain inclines to move slate up and down the quarry faces.

What remains

The quarry workers' complex of buildings survives almost complete, including cottages, a saw mill and a weighbridge.

Workers' cottages, a saw mill and a weighbridge, alongside the 17th-century house that gave the quarry its name.

Abandoned workings can be dangerous — unstable ground, uncapped shafts, flooding and bad air are common even where a site looks safe from the surface. This entry describes history and general location only; it is not an access guide.

Recorded claims

Individual factual claims, each attached to the source(s) that support it below. Where sources disagree, both are kept.

• Pen-y-Bryn Quarry takes its name from a 17th-century house on the site, which continued to be lived in throughout the quarry's working life and remained occupied until after the Second World War. ¹
• The quarry produced distinctive purple and blue slates, divided by a thin vein of green slate between them. ²
• Between 1836 and 1844, Pen-y-Bryn and the neighbouring Cloddfa'r Lon quarry used water-wheel technology connected by rods to pumps; both quarries later used chain inclines, a technology invented locally, to move slate. ²
• The complex of buildings used by the quarry's workers survives today almost complete, including their cottages, a saw mill and a weighbridge. ¹

Photographs & further reading

This page doesn't try to reproduce everything — these are the best original sources found for this mine.

Sources

1. (secondary) Pen-y-Bryn quarry cottages, Nantlle — History Points
2. (secondary) Slate industry in the Nantlle Valley — Wikipedia

Record created: 30 August 2026 · Last researched: 31 August 2026