Causeway, Llanllyfni, Gwynedd

Coordinates

Latitude: 53.0523 / 53°3'8"N

Longitude: -4.2457 / 4°14'44"W

OS Eastings: 249575

OS Northings: 352921

OS Grid: SH495529

Mapcode National: GBR 5K.CM44

Mapcode Global: WH43T.RJFW

Plus Code: 9C5Q3Q23+WP

Entry Name: Causeway

Listing Date: 10 December 1992

Last Amended: 21 July 2000

Grade: II

Source: Cadw

Source ID: 22902

Building Class: Industrial

ID on this website: 300022902

Location: Located off the B 4418 to the north of Dorothea House, beginning beyond Pont Wythdir and running north-east for approximately 100m across marshy ground with a spoil heap to the north-west on the south

County: Gwynedd

Community: Llanllyfni

Locality: Nantlle

Traditional County: Caernarfonshire

Tagged with: Architectural structure

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Nantlle

History

The Nantlle Vale has a long and important history of slate quarrying dating from Roman times. The Dorothea Quarry was a large open-cast pit formed out of 6 small pits, the earliest of which was sunk c1820. The causeway was probably constructed sometime between 1805 and 1830 as part of a road laid to transport slate from the Tan-yr-allt Quarry (opened in 1805), and perhaps others on the south side of the Nantlle Vale, up to the main east-west road near Talysarn Quarry (opened in 1790) and the Nantlle Railway (opened in 1828). This road originally passed the western edge of the Dorothea Quarry but it was cut at the north-east end following a C20 cliff fall at the South Dorothea Quarry (opened in 1860) and so it remains in its earlier C19 form.

Exterior

Causeway constructed of slate rubblestone with some boulders to the base and quoins; flat coping. Both sides have central segmental arch with flanking tapered pilasters together with voussoirs and arch-ring set below a string course which continues either side over square-headed and slate-roofed culverts, 2 to south-west end and 3 to north-east; the former are still open all the way through; rubble soffit to central arch. The parapet is beween 1.2m and 1.5m high and the width is approximately 5m. The road level climbs towards the north-east end where the parapet has partly collapsed.

Reasons for Listing

Listed for its special interest to the history of the Welsh slate industry as a rare example of an unaltered early C19 slate road at a particularly important quarry.

External Links

External links are from the relevant listing authority and, where applicable, Wikidata. Wikidata IDs may be related buildings as well as this specific building. If you want to add or update a link, you will need to do so by editing the Wikidata entry.

Recommended Books

Other nearby listed buildings

II* Engine House, Boilerhouse, Bunker and remains of chimney to south
On a ridge of bastard rock which divides the main Dorothea Quarry from the South Dorothea Quarry; located by the side of the road access to the quarry.
II South-western aerial ropeway revetment, incline and associated buildings
Located above the south side of the North Dorothea Slate Quarry, between the Cornish beam engine house to the west and the ruins of the former slate mill to the east.
II Capel Mawr, Sunday School and railed steps to chapel forecourt
Located in a commanding position at the eastern end of Talysarn with its Sunday School directly to the east, the chapel is set high above the road at the top of its own steps.
II Tunnel Portal and Tunnel
Located in the hillside to the north of Talysarn Hall.
II Seion Congregational Church
Situated in an elevated position amidst terraced housing approximately half way up Cavour Street; in front of the chapel is a small forecourt behind an irregularly coursed rubblestone wall, topped by
II North-eastern aerial ropeway revetment, incline and associated buildings
Located above the east side of the North Dorothea Slate Quarry between Pen-y-Bryn to the north-east and the ruins of the former slate mill to the south-east.
II Strainer arches and retaining walls
Located to the south of Pen-y-bryn, the strainer arches and walls retain the slate waste tips flanking the route of the Dorothea Quarry branch of the former Nantlle Railway.
II Pen-y-bryn
Located at the end of a track on the north side of the old Talysarn to Nantlle Road.

British Listed Buildings

History in Structure

Causeway

A Grade II Listed Building in Llanllyfni, Gwynedd