Braichgoch Slate Mine

Overview

The largest slate mine south of Blaenau Ffestiniog at its Victorian peak, worked at Corris Uchaf from 1787 until 1970, whose underground caverns today host the tourist attraction King Arthur's Labyrinth.

History

David Williams leased quarrying and mineral rights at Gaewern and Braich Goch from John Edwards, representing the Vane estate, in 1787, with slate extraction beginning at Gaewern by 1812 under the Merionethshire Slate Company. Quarrying at Braich Goch itself began in 1836 under the North Wales Slate & Slab Company. Ownership changed hands repeatedly over the following decades: Arthur Causton, a civil engineer, took the lease in 1843; the company was reformed as the Braich Goch Slate and Slab Company in 1851; and the Birley family purchased the lease in 1859, establishing Braich Goch Slate Quarry Ltd, which absorbed the neighbouring Gaewern quarry in 1880. The mine reached its peak in the mid-1890s, when it employed 350 men and produced over 6,000 tons of finished slate a year, making it the largest slate quarry south of Blaenau Ffestiniog. Rising costs and falling demand brought the company down in 1906, and the mine closed; it reopened after the First World War but worked only sporadically thereafter before closing for good around 1970-71. Part of its underground workings were commercialised in 1994 as King Arthur's Labyrinth, a boat-ride attraction built around Arthurian legend inside the old slate caverns, alongside the separate, more conventional Corris Mine Explorers, which shows visitors the mine's genuine 19th-century working conditions.

Workings

Underground slate mine workings at Braich Goch, later absorbing the neighbouring Gaewern quarry from 1880.

Closure

Closed in 1906 amid falling slate demand, reopened after the First World War, and closed for good around 1970-71.

What remains

Part of the underground workings are open to the public as King Arthur's Labyrinth, a fantasy-themed tourist attraction, and as the separate Corris Mine Explorers, alongside the Corris Craft Centre on the surface site.

The Corris Craft Centre occupies the surface site; underground, King Arthur's Labyrinth and Corris Mine Explorers preserve and present the old workings.

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.

• By the mid-1890s Braichgoch employed 350 men and produced over 6,000 tons of finished slate a year, the largest slate quarry south of Blaenau Ffestiniog. ¹
• The mine closed in 1906 amid falling slate demand, reopened after the First World War, worked only sporadically afterward, and closed for good around 1970-71; part of its workings were commercialised as the King Arthur's Labyrinth tourist attraction in 1994. ¹

Photographs & further reading

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

Images

Sources

1. (secondary) Braichgoch slate mine — Wikipedia
2. (observational) King Arthur's Labyrinth — Wikimedia Commons (Tom Parnell)

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