Cymerau Quarry

Locationhalf a mile north of Aberllefenni, Gwynedd — 52.6929, -3.7960 (approximate)
CommoditySlate
TypeSlate
WorkedCommenced around 1860, following the earlier success of the neighbouring Ratgoed quarry.–Closed for good in October 1946, alongside Ratgoed.
Maximum depthNo reliable depth figure has yet been located.
OperatorsInigo Jones and Company (1918–?)
Status Researched

Overview

A slate quarry half a mile north of Aberllefenni, worked from around 1860 to 1946, whose original underground chambers lay below the water table and required continuous pumping, sharing the remote Ratgoed Tramway with its better-known neighbour Ratgoed quarry.

History

Cymerau quarry began operating around 1860, following the earlier success of the neighbouring Ratgoed quarry to the north. Slate was extracted from five underground chambers working the Narrow Vein -- the highest-quality slate in the Abercorris Group -- which lay below the water table and required continuous pumping by waterwheel. In 1864 the Ratgoed Tramway opened, a 2 ft 3 in gauge horse-worked line connecting both Cymerau and Ratgoed to the newly built Corris Railway at Aberllefenni; the tramway's arrival prompted significant expansion at the quarry, with finished slate travelling downhill to the tramway by gravity while ponies hauled the empty wagons back up. By 1878 the quarry was owned by H. R. Hughes and his nephew. A second quarry opened around 1880, between the original workings and Ratgoed, consisting of surface pits linked by incline, with slate transported down to a southern mill for processing; at its height the combined workings employed over 100 men, whose slate travelled via the quarry's own private wagons along the Ratgoed Tramway and onward on the Corris Railway toward Machynlleth. The quarry closed during the First World War and was reopened at greatly reduced scale by the Inigo Jones company of Groeslon, producing just three tons of finished slab in 1921 with only three employees; a modest recovery took employment to 14 workers by 1927, before falling again to six by the outbreak of the Second World War. Limited wartime production continued until the quarry finally closed in October 1946, at the same time as Ratgoed.

Workings

Slate worked from underground chambers below the water table (pumped by waterwheel) and, from around 1880, a second surface-pit working linked by incline to a southern mill; finished slate ran by gravity to the quarry's own private wagons on the horse-worked Ratgoed Tramway.

Closure

Closed in October 1946, at the same time as the neighbouring Ratgoed quarry, after a long decline from over 100 workers at its Victorian peak to just six by the start of the Second World War.

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.

Sources

  1. (secondary) Cymerau quarry — Wikipedia
  2. (secondary) Ratgoed Tramway — Wikipedia

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