The Stanley Embankment (known locally as the Cob) is a railway, road and cycleway embankment that crosses the Cymyran Strait in Wales, connecting the Island of Anglesey and Holy Island. It carries both the North Wales Main Line railway, which runs from

Crewe Crewe () is a railway town and civil parish in the unitary authority of Cheshire East in Cheshire, England. At the 2021 United Kingdom census, 2021 census, the parish had a population of 55,318 and the built-up area had a population of 74,120. ...

Holyhead Holyhead (; , "Cybi's fort") is a historic port town, and is the list of Anglesey towns by population, largest town and a Community (Wales), community in the county of Isle of Anglesey, Wales. Holyhead is on Holy Island, Anglesey, Holy Island ...

, and the

A5 road A5 Road may refer to: ;Africa * A5 highway (Nigeria), a road connecting Lagos and Ibadan * A5 road (Zimbabwe), a road connecting Harare and Bulawayo ;Americas * Quebec Autoroute 5, a road in Quebec, Canada * County Route A5 (California) or Bowm ...

between London and Holyhead. The embankment was designed by, and its construction overseen by,

Thomas Telford Thomas Telford (9 August 1757 – 2 September 1834) was a Scottish civil engineer. After establishing himself as an engineer of road and canal projects in Shropshire, he designed numerous infrastructure projects in his native Scotland, as well ...

and was named after the

Stanley family The Stanley family (or Audley-Stanley family) is an English family with many notable members, including the Earl of Derby, Earls of Derby and the Baron Audley, Barons Audley who descended from the early holders of Audley, Staffordshire, Audley ...

who were significant benefactors to the area.Hughes, Margaret: ''"Anglesey from the sea"'', page 73. Gwasg Carreg Gwalch, 2001 Prior to its construction, the fastest route to Holyhead from the island's mainland was via the old stone bridge at Four Mile Bridge (). When the A5 road was being constructed between London and the

Port of Holyhead file:Just inside the 'new' harbour at Holyhead port - geograph.org.uk - 579776.jpg, 300px, Just inside the 'New' harbour at Holyhead port., alt=Port of Holyhead From geograph.org.uk 8 October 2007 The Port of Holyhead () is a commercial and fe ...

, a more direct route was needed. Construction of the embankment started in 1822 and was completed a year later. It is a total of long,Jones, G: ''"Anglesey Railways"'', page 17. Gwasg Carreg Gwalch, 2005 and is significantly wider at the base () than at the top (). The embankment to Holy Island was constructed using rock and materials excavated from a site on the Anglesey side. A workers' hamlet grew up around the artificially-created depression, which was nicknamed "the valley".Hughes, Margaret: ''"Anglesey Villages"'', page 71. Gwasg Carreg Gwalch, 2003 After work ended, the settlement remained developing into a medium-sized village known as

Valley A valley is an elongated low area often running between hills or mountains and typically containing a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams over ...

. A year after opening, the embankment was partly damaged in a storm in 1824. In the 1840s, the embankment was chosen to carry the North Wales Main Line to the Port of Holyhead, rather than build an entirely new crossing. Work to significantly widen the structure was completed in 1848. To allay concerns that passing

train A train (from Old French , from Latin">-4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , from Latin , "to pull, to draw") is a series of connected vehicles th ...

s might startle horse drawn traffic using the embankment, a tall stone dividing wall was built between the road and the railway. The embankment remained the only major crossing between Holy Island and Anglesey for more than 175 years. In 2001 it was superseded by a new wider embankment, which was built as part of the final section of the A55 North Wales Expressway. The section completely bypassed Valley and the old A5 at this point. The new crossing, which carries the modern A55 dual carriageway, was built parallel to the Stanley Embankment, following its north–south alignment.

References

{{coord, 53.2899, -4.5825, type:landmark_region:GB, display=title Bridges completed in 1823 Railway bridges in Wales Road bridges in Wales Bridges in Anglesey Works of Thomas Telford Valley, Anglesey Holyhead Trearddur