Cambergi Quarry

Overview

A short-lived slate quarry in Cwm Hengae near Aberllefenni, also known as Wenallt quarry, whose founding company raised substantial public capital in 1873 only to go bankrupt within months of production actually starting.

History

The Cambergi Slate Company Limited was formed in 1873 to work a slate vein in Cwm Hengae, west of Aberllefenni, offering 10,000 shares at £20 each to the public -- £200,000 of capital, a very substantial sum for a single quarry venture. It took the company two years to build the mill and incline before quarrying finally began around 1875, by which point the construction costs already incurred had exhausted its finances: the company operated the quarry for only a few months in 1875 before going bankrupt. The lease passed to the Griffiths family, led by Griffith Williams Griffiths, who had already worked a smaller quarry of his own at the top of the same valley for nearly a decade. Cambergi's slate proved to be of poor quality, and in 1877 Griffiths began developing a new quarry, Hengae, on the opposite side of the valley instead. Cambergi closed briefly in 1879 amid a wider fall in slate prices that shut several quarries in the district at once, reopened by 1880, and continued under Griffiths, despite the difficulties, until just before the turn of the century -- it was already marked disused on the 1900 Ordnance Survey map. Output had no direct rail connection: despite an early proposal for a branch of the Corris Railway to reach the Cambergi mill directly, it was never built, and finished slate was instead carted to the tramway at Aberllefenni quarry or all the way to Aberllefenni station.

Workings

Seven terraced levels connected by a steep four-pitch incline down to the valley floor; a mill at the foot of the incline contained nine saw tables and a planer for finishing the slate.

Closure

Already shown as disused on the 1900 Ordnance Survey map; no exact closure date is recorded.

What remains

Ruins of the slate-built mill, including its nine saw tables and planer, survive on the valley floor, along with the seven worked terraces, waste tips and the four-pitch incline.

The ruined mill building with its saw tables and planer, seven terraced quarry levels, waste tips, and the four-pitch incline.

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.

• The Cambergi Slate Company Limited was formed in 1873 with £200,000 raised through public shares, but went bankrupt after operating the quarry for only a few months in 1875, having spent most of its capital on construction. ¹
• Griffith Williams Griffiths took over the lease in 1875, found the slate to be poor quality and began developing the separate Hengae quarry from 1877, but continued working Cambergi until just before 1900, when it was recorded as disused on the Ordnance Survey map. ¹
• Cambergi's boom-and-bankruptcy history was typical of the wider Corris slate district, whose quarries cycled repeatedly through failure and reopening under new owners even as the Corris Railway itself, once taken over by Imperial Tramways Ltd in 1878, became a genuinely prosperous concern in its own right. 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) Cambergi quarry — Wikipedia
2. (secondary) Cwmodyn or Abercorris Quarry — Pugh Family Genealogy — Grant Online

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