History in Structure

This site is entirely user-supported. See how you can help.

Dolgoch Viaduct

A Grade II Listed Building in Bryn-crug, Gwynedd

More Photos »
Approximate Location Map
Large Map »


Latitude: 52.6215 / 52°37'17"N

Longitude: -3.995 / 3°59'42"W

OS Eastings: 265046

OS Northings: 304504

OS Grid: SH650045

Mapcode National: GBR 8W.7WJC

Mapcode Global: WH576.LCTN

Entry Name: Dolgoch Viaduct

Listing Date: 15 August 2000

Last Amended: 19 September 2000

Grade: II

Source: Cadw

Source ID: 23900

Building Class: Transport

Location: The viaduct carries the Tal-y-llyn narrow gauge railway over the Nant Dol-goch, reached by pathway from the B4405 past Dolgoch Farm.

County: Gwynedd

Community: Bryn-crug

Community: Bryn-Crug

Locality: Bryn Crug

Traditional County: Merionethshire

Find accommodation in


The Talyllyn Railway was incorporated by the Talyllyn Railway Act, 28 & 29 Victoria cap cccxv of 5 July 1865. Its primary purpose was to carry slate products from the productive Bryn Eglwys quarry to the Aberystwyth & Welsh Coast Railway at Tywyn. The line was surveyed and engineered by James Swinton Spooner. A gauge of 2ft 3in (0.686m) was adopted. The greatest single obstacle was the gorge of Nant Dolgoch, which was bridged by a viaduct to maintain an even gradient. The railway opened to goods and mineral traffic in July 1866 and passengers in December 1866. Traffic declined from the late 1930s onwards but the railway continued in operation for passengers and goods until 1950, despite the closure of the slate quarries in 1947. Closure and dismantling were held off due to the owner's insistence that the railway should continue to operate during his lifetime. The railway became notable as the first to be rescued from closure by voluntary effort.


The viaduct is built of red brick with flush margin-drafted stone dressings. Three segmental spans carried on two tall slightly tapered piers each 10.3m high above a chamfered base, carrying the track 15.4m (50ft 6in) above the water. The centre arch spans 9.2m and the overall width is 2.8m. There is a triangular refuge cantilevered off at mid span, and it has 4 simple horizontal railings threaded through iron stanchions, set on the low parapets. Stone chamfered revetments. The bridge was rebuilt above the arch tops in 1969-1970 and steel bars with square restraining plates set below the parapets.

Reasons for Listing

Included as a fine and simply designed railway structure for a narrow gauge railway, one of the few elements along the line to be in its original condition.

Recommended Books

Other nearby listed buildings

  • II Farm building associated with Nant-y-mynach
    The building stands beside the road leading N from the B4405 in the direction of Abertrinant, just below a sharp bend.
  • II Mile Marker
    The marker is set in a bank on a corner SW of Ty Gwyn.
  • II Mile marker
    The milestone stands in the S verge of the main road from Tywyn to Dolgellau, E of Dol-Deheuwydd

BritishListedBuildings.co.uk is an independent online resource and is not associated with any government department. All government data published here is used under licence. Please do not contact BritishListedBuildings.co.uk for any queries related to any individual listed building, planning permission related to listed buildings or the listing process itself.

British Listed Buildings is a Good Stuff website.