Tal-y-sarn Quarry

Overview

A slate quarry in the Nantlle Valley beside the village of Talysarn, worked predominantly for roofing slate through a mix of open-pit and underground chambers from the early-to-mid 19th century until its 20th-century closure, and connected via internal tramways to the Nantlle Railway.

History

Tal-y-sarn Quarry lies close to the village of Talysarn in the Nantlle Valley, forming part of a wider cluster of slate workings that includes the far larger Dorothea quarry immediately to the west. First developed in the early to mid-19th century, it was worked predominantly for roofing slate -- more modest in scale than Dorothea's vast pit, but a significant contributor to the valley's 19th-century slate boom in its own right -- through a mix of open-pit and underground chambers. Slate was split and dressed on site before being carried by internal tramways to connect with the Nantlle Railway, a horse-drawn tramway opened in 1828 that carried slate from Tal-y-sarn and the valley's other quarries down to the port at Caernarfon; Dorothea itself used the line to despatch its own slate from 1829 until as late as 1959. As Dorothea's own workings expanded through the 19th century, they grew to encroach on Talysarn village itself, eventually forcing its relocation to the west; some of the original village's buildings remained in industrial use by the quarries afterwards, and their ruins survive today. Tal-y-sarn Quarry closed in the 20th century as the wider Welsh slate industry declined and larger, consolidated operations elsewhere in the valley made smaller sites such as this one uneconomic to continue running.

Workings

Worked for roofing slate through a mix of open-pit and underground chambers, with slate split and dressed on site before transport by internal tramway to the Nantlle Railway.

What remains

Now quiet and partially reclaimed by nature, offering a more intimate and less disturbed view of Nantlle Valley slate working than the neighbouring Dorothea quarry.

Former quarry workings and, nearby, the surviving ruins of the original Talysarn village buildings displaced by Dorothea's expansion.

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.

• Tal-y-sarn Quarry was first developed in the early to mid-19th century and worked predominantly for roofing slate through a mix of open-pit and underground chambers, connected by internal tramways to the Nantlle Railway. ¹
• The Nantlle Railway, a horse-drawn tramway opened in 1828, carried slate from Tal-y-sarn and other Nantlle Valley quarries to the port at Caernarfon; the neighbouring Dorothea quarry used the same line to despatch slate from 1829 until 1959. ²
• As the neighbouring Dorothea quarry's workings expanded through the 19th century, they encroached on Talysarn village itself, forcing its relocation to the west; some of the original village's buildings remained in industrial use by the quarries, and their ruins survive today. ²

Photographs & further reading

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

Sources

1. (secondary) Slate industry in the Nantlle Valley — Wikipedia
2. (secondary) Dorothea quarry — Wikipedia

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