Ancient Monuments

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Treforys Deserted Quarry Settlement

A Scheduled Monument in Dolbenmaen, Gwynedd

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Latitude: 52.9865 / 52°59'11"N

Longitude: -4.1452 / 4°8'42"W

OS Eastings: 256094

OS Northings: 345396

OS Grid: SH560453

Mapcode National: GBR 5P.HTT4

Mapcode Global: WH55D.96C9

Entry Name: Treforys Deserted Quarry Settlement

Scheduled Date: 1 June 2000

Source: Cadw

Source ID: 1062

Cadw Legacy ID: CN321

Schedule Class: Civil

Category: Settlement

Period: Post Medieval/Modern

County: Gwynedd

Community: Dolbenmaen

Traditional County: Caernarfonshire


The monument consists of the deserted remains of a village built in the 1850s to serve Gorseddau Slate Quarry (also scheduled CN303). A planned village was laid out after the Gorseddau Quarry was taken over in 1854 by Robert Gill and John Harris and developed by the German mining engineer Henry Tobias Tschudy von Uster. The quarry was served by its own railway to the magnificent slab mill at Ynysypandy (also scheduled CN160) and thence to Porthmadog. It was said of the quarry, 'everything that could facilitate the works was produced, nothing being wanted but the slate vein.' It operated for only 12 years, and closed finally in 1871.

The village is laid out on the hillside above the railway a kilometre west of the quarry. It consisted of three parallel streets with eighteen pairs of rubble-built, single-storey cottages. The streets with their straight flanking walls survive and the ruins of the cottages stand to between 1 and 3m in height. Traces of watercourses and garden plots are visible between the streets.

The monument is of national importance for its potential to enhance our knowledge of settlement organisation. It retains significant archaeological potential for the study of workers' settlement and material culture, with a strong probability of the presence of associated archaeological features and deposits. The monument has significant group value with the outstanding remains of Gorseddau Quarry and Ynysypandy Slate Mill.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.

Source: Cadw

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