View source for Pontcysyllte Aqueduct

{{Short description|Waterway in Wales}}
{{Use dmy dates|date=March 2015}}
{{Use British English|date=September 2014}}
{{Infobox aqueduct navigable
|name             = Pontcysyllte Aqueduct
|native_name      = Traphont Ddŵr Pontcysyllte
|image            = pontcysyllte aqueduct arp.jpg|
|image_size       = 
|image_caption    = 
|carries          = [[Llangollen Canal]]
|crosses          = [[River Dee, Wales|River Dee]]
|location         = [[Froncysyllte]], [[Wrexham County Borough|Wrexham]], [[Wales]]
|os_grid_reference= SJ270420
|maintained       = [[Glandŵr Cymru – the Canal & River Trust]]
|designer         = [[Thomas Telford]]
|material1        = [[Cast iron]]
|material2        = Stone
|number_spans     = 18
|piers_in_water   = 4
|mainspan         =
|length           = {{cvt|336|yd}}
|width            = {{cvt|12|ft}}
|height           = {{cvt|126|ft}}
|depth            = {{cvt|5|ft|3|in}}
|traversable      = Yes
|towpath          = East side
|clearance_above  =
|clearance_below  =
|begin            = 25 July 1795
|complete         =
|open             = 26 November 1805
|heritage         = [[Listed building|Grade I listed]]
|closed           =
|coordinates      = {{Coord|52|58|14|N|03|05|16|W|region:GB_scale:10000_type:landmark|display=inline,title}}
|extra            = 
  {{Infobox UNESCO World Heritage Site
  |child = yes
  |Official_name = Pontcysyllte Aqueduct and Canal
  |ID = 1303
  |Year = 2009
  |Criteria = Cultural: i, ii, iv
  |Area = 105 ha
  |Buffer_zone = 4,145 ha 
  }}
}}
The '''Pontcysyllte Aqueduct''' ({{IPA|cy|ˌpɔntkəˈsəɬtɛ}}; {{langx|cy|Traphont Ddŵr Pontcysyllte}}) is a [[navigable aqueduct]] that carries the [[Llangollen Canal]] across the [[River Dee, Wales|River Dee]] in the Vale of Llangollen in northeast [[Wales]].

The 18-arched stone and [[cast iron]] structure is for use by [[narrowboat]]s and was completed in 1805 having taken ten years to design and build. It is {{convert|12|ft|m|abbr=off}} wide and is the longest aqueduct in [[Great Britain]] as well as the highest canal aqueduct in the world. A [[towpath]] runs alongside the watercourse on one side.<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/wales/north_east/8115190.stm |date=27 June 2009 |title=Aqueduct crowned world 'wonder' |work=BBC News}}</ref><ref>{{cite news |url=https://www.telegraph.co.uk/news/earth/earthnews/3321311/Pontcysyllte-Aqueduct-in-World-Heritage-bid.html |last=Clover |first=Charles |work=Daily Telegraph |title=Pontcysyllte Aqueduct in World Heritage bid |date=11 January 2008}}</ref>

The aqueduct was to have been a key part of the central section of the proposed [[Ellesmere Canal]], an industrial waterway that would have created a commercial link between the [[River Severn]] at [[Shrewsbury]] and the [[Port of Liverpool]] on the [[River Mersey]]. Although a less expensive construction course was surveyed further to the east, the westerly high-ground route across the Vale of Llangollen was preferred because it would have taken the canal through the mineral-rich coalfields of [[North East Wales]]. Only parts of the canal route were completed because the expected revenues required to complete the entire project were never generated. Most major work ceased after the completion of the Pontcysyllte Aqueduct in 1805.

The structure is a [[Grade I listed buildings in Wrexham County Borough|Grade I listed building]]<ref>{{cite web|url=http://www.wrexham.gov.uk/english/planning_portal/publications/listed_build_exhib/pontcysyllte_aque.htm|title=Listed Buildings: Pontcysyllte Aqueduct, Trevor|website=Wrexham.gov.uk|access-date=25 May 2007|url-status=dead|archive-url=https://web.archive.org/web/20081013142701/http://www.wrexham.gov.uk/english/planning_portal/publications/listed_build_exhib/pontcysyllte_aque.htm|archive-date=13 October 2008|df=dmy-all}}</ref> and part of a [[UNESCO]] [[World Heritage Site]].

==Etymology==
The name ''Pontcysyllte'' is [[Welsh language|Welsh]] for "Cysyllte Bridge" or "Bridge of Cysyllte", Cysyllte being the [[township (England)|township]] of the old parish of [[Llangollen]] in which the southern end of the bridge lies.<ref name="DictionaryPlaceNamesWales">{{cite book|last=Owen|first=Hywel Wyn|title=A Dictionary of Place-Names in Wales|year=2007|publisher=Gomer Press|location=Ceredigion, Wales|isbn=978-1-84323-901-7}}</ref>  The northern end of the bridge was in Trefor Isaf township, also in Llangollen parish.{{Citation needed|date = November 2019}}

Other translations such as "bridge of the junction" or "bridge that links" are modern [[false etymology|false etymologies]], derived from the name's apparent similarity to the word ''{{lang|cy|cysylltau}}'' (plural of ''cyswllt'') which means connections or links.<ref>[http://geiriadur.ac.uk/gpc/gpc.html?cyswllt cyswllt]</ref>

==History==
[[File:WalesC0047.jpg|thumbnail|The aqueduct viewed from the valley below]]
The aqueduct was designed by civil engineers [[Thomas Telford]] and [[William Jessop]] for a location near an 18th-century road crossing, [[Pont Cysyllte]]. After the westerly high-ground route was approved, the original plan was to create a series of locks down both sides of the valley to an embankment that would carry the [[Ellesmere Canal]] over the River Dee. After Telford was hired the plan was changed to an aqueduct that would create an uninterrupted waterway straight across the valley. Despite considerable public scepticism, Telford was confident his construction method would work because he had previously built a cast-iron trough aqueduct – the [[Longdon-on-Tern Aqueduct]] on the [[Shrewsbury Canal]].<ref>{{cite web|title=Longdon-on-Tern Aqueduct|url=http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=308|website=Engineering Timelines|access-date=28 January 2017|quote=It is still visible in the middle of a field, though the canal was closed in 1944 and dewatered in the 1950s.}}</ref>

The aqueduct was one of the first major feats of [[civil engineering]] undertaken by Telford, who was becoming one of Britain's leading industrial [[civil engineer]]s; although his work was supervised by Jessop, the more experienced canal engineer. Ironwork was supplied by [[William Hazledine]] from his foundries at [[Shrewsbury]] and nearby [[Cefn Mawr]]. The work, which took around ten years from design to construction, cost around of [[Pound sterling|£]]47,000. Adjusted for inflation this is equivalent to no more than £{{formatnum:{{Inflation|UK|47000|1805|r=-4}}}} in {{Inflation-year|UK}}{{Inflation-fn|UK|df=y}}, but represented a major investment against the contemporary GDP of some £400&nbsp;million.{{citation needed|date=January 2019}}

The Pontcysyllte aqueduct officially opened to traffic on 26 November 1805. A plaque commemorating its inauguration reads:
<blockquote>The nobility and gentry, the adjacent Counties having united their efforts with the great commercial interests of this country. In creating an intercourse and union between England and North Wales by a navigable communication of the three Rivers, Severne {{sic}} Dee and Mersey for the mutual benefit of agriculture and trades, caused the first stone of this aqueduct of Pontcysyllty {{sic}}, to be laid on the 25th day of July MDCCXCV [1795]. When [[Richard Myddelton (1764–1796)|Richard Myddelton]] of Chirk, Esq, M.P. one of the original patrons of the Ellesmere Canal was Lord of this manor, and in the reign of our Sovereign George the Third. When the equity of the laws, and the security of property, promoted the general welfare of the nation. While the arts and sciences flourished by his patronage and the conduct of civil life was improved by his example.
</blockquote>

The bridge is {{convert|336|yd|m|abbr=on}} long, {{convert|12|ft|m|abbr=on}} wide and {{convert|5|ft|3|in|m|abbr=on}} deep.<ref>{{cite web |title=Pontcysyllte Aqueduct |url=http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=100 |archive-url=https://web.archive.org/web/20211120171754/http://www.engineering-timelines.com/scripts/engineeringItem.asp?id=100 |archive-date=20 November 2021 |access-date=28 January 2017 |website=Engineering Timelines}}</ref> It consists of a [[cast iron]] trough supported {{convert|126|ft|m|abbr=on}} above the river on iron arched ribs carried on eighteen hollow masonry piers (pillars). Each of the 18 spans is {{convert|53|ft|m|abbr=on}} wide. With the completion of the aqueduct, the next phase of the canal should have been the continuation of the line to [[Moss Valley, Wrexham]] where Telford had constructed a feeder reservoir lake in 1796. This would provide the water for the length of canal between [[Trevor Basin]] and [[Chester]]. The plan to build this section was cancelled in 1798, and the isolated feeder and a stretch of navigation between Ffrwd and a basin in [[Summerhill, Wrexham|Summerhill]] was abandoned. Remnants of the feeder channel are visible in [[Gwersyllt]]. A street in the village is still named {{langnf|cy|Heol Camlas|canal way}}.<ref name="coedpoeth.minerahistory.com">{{cite web|url=http://www.coedpoeth.minerahistory.com/timeline.html|title=Local Timeline|website=Coedpoeth.minerahistory.com|access-date=4 July 2012|archive-url=https://web.archive.org/web/20110714095706/http://www.coedpoeth.minerahistory.com/timeline.html|archive-date=14 July 2011|url-status=dead}}</ref> The physical construction was undertaken by John Simpson (d.1815) of [[Shrewsbury]].<ref>Dictionary of British Sculptors 1660-1851 by Rupert Gunnis</ref>

With the project incomplete, [[Trevor Basin]] just over the Pontcysyllte aqueduct would become the canal's northern terminus. In 1808 a feeder channel to bring water from the River Dee near [[Llangollen]] was completed. In order to maintain a continual supply, Telford built an artificial [[weir]] known as the [[Horseshoe Falls (Wales)|Horseshoe Falls]] near [[Llantysilio]] to maintain water height.

Subsequently, the Plas Kynaston Canal was built to serve industry in the Cefn Mawr and Rhosymedre areas in the 1820s. There might have been another canal extension ("Ward's") but detailed records do not survive.<ref name="Plas Kynaston Canal by P Brown">{{cite web|url=http://plaskynastoncanalgroup.org/app/download/5780802223/Plas+Kynaston+Canal+by+P+Brown.pdf |title=Plas Kynaston Canal by P Brown|website=Plaskynastoncanalgroup.org}}</ref> Goods traffic was brought down to the canal by the [[Ruabon Brook Tramway]] which climbed towards Acrefair and Plas Bennion. This railway was eventually upgraded to steam operation and extended towards [[Rhosllannerchrugog]] and [[Wrexham]].<ref name="Plas Kynaston Canal by P Brown"/>

In 1844, the Ellesmere and [[Chester Canal]] Company, which owned the broad canals from [[Ellesmere Port]] to [[Chester]] and from Chester to [[Nantwich]], with a branch to [[Middlewich]], began discussions with the narrow [[Birmingham and Liverpool Junction Canal]], which ran from Nantwich to Autherley, where it joined the [[Staffordshire and Worcestershire Canal]]. The two companies had always worked together, in a bid to maintain their profits against competition from the railways, and amalgamation seemed to be a logical step. An agreement was worked out by August, and the two companies then sought an [[act of Parliament]] to authorise the takeover. This was granted as the [[Ellesmere and Chester Canal Company Act 1845]] ([[8 & 9 Vict.]] c. ii) on 8 May 1845, when the larger Ellesmere and Chester Canal Company was formed.<ref>{{harvnb |Hadfield |1985 |pp=188–189}}</ref>

[[File:Pontcysyllte aqueduct plaque.jpg|thumb|upright|Plaque commemorating the construction of the Pontcysyllte Aqueduct between 1795 and 1805 by Thomas Telford]]
In 1846, the canal and the aqueduct became part of the [[Shropshire Union Railways and Canal Company]]. But the intent of the merger was to build railways at a reduced cost, by using the existing routes of the canals they owned.<ref name=nic>{{cite book|title=[[Nicholson Guides|Nicholson Waterways Guide]]|volume=4|year=2006|publisher= Harper Collins Publishing Ltd| isbn= 0-00-721112-0}}</ref> By 1849, the plan to turn canals into railways had been dropped.<ref name=nic/> As the aqueduct was largely in an area that was served by railways owned by the [[Great Western Railway]], the [[London and North Western Railway]] was more than happy for the canal to remain open as long as it remained profitable.{{citation needed|date=May 2023}}{{what?|date=May 2023}} With the start of the [[First World War]] in 1914, the Shropshire Union – of which the Pontcysyllte aqueduct was a part – served the war effort with its fleet of more than 450 narrow boats.<ref name=nic/>

Commercial traffic on the canal greatly declined after a waterway breach near [[Newtown, Powys]] (now part of the Montgomery Canal) in 1936. By 1939 boat movements across the aqueduct to [[Llangollen]] had ceased. The canal was formally closed to navigation under the [[London Midland and Scottish Railway (Canals) Act 1944]] ([[8 & 9 Geo. 6]]. c. ii)). On 6 September 1945, due to inadequate maintenance, the canal breached its banks east of [[Llangollen]] near [[Sun Bank Halt]]. The flow of hundreds of tons of water washed away the embankment of the railway further down the hill, tearing a {{convert|40|yd|adj=on}} crater {{convert|50|ft}} deep.<ref>{{cite book|title=The Shell Book of Inland Waterways|author=Hugh McKnight|publisher=[[David & Charles]]|year=1987|isbn=0-7153-8239-X|page=28}}</ref> This caused the first traffic of the morning, a mail and goods train composed of 16 carriages and two vans, to crash into the breach, killing one and injuring two engine crew.<ref>{{cite web|url=http://www.llangollen-railway.co.uk/hist/accid.html|archive-url=https://web.archive.org/web/20070101023203/http://www.llangollen-railway.co.uk/hist/accid.html|url-status=dead|archive-date=1 January 2007|title=History of the Llangollen Railway - Sun Bank Halt accident|date=1 January 2007|access-date=26 November 2018}}</ref>

The aqueduct was saved (despite its official closure to waterway traffic) because it was still required as a water feeder for the remainder of the [[Shropshire Union Canal]]. The aqueduct also supplied drinking water to a reservoir at [[Hurleston]]. In 1955 the Mid & South East Cheshire Water Board agreed to maintain the canal securing its future.<ref>{{cite book|title=Narrowboat Nomads: Living the Dream on the English Waterways|first=Steve|last= Haywood|publisher=Summersdale|year=2015 |url=https://books.google.com/books?id=lBIgCgAAQBAJ&pg=PT128|isbn=9781783726110}}</ref>

In the latter half of the 20th century, leisure boating traffic began to rise. In a rebranding exercise by [[British Waterways]] in the 1980s, the former industrial waterway was renamed the [[Llangollen Canal]]. It has since become one of the most popular canals for holidaymakers in Britain because of its aqueducts and scenery. The Pontcysyllte Aqueduct is now maintained and managed by the [[Canal & River Trust]] (branded Glandŵr Cymru in Wales). [[Otter]]s have been seen in the area.<ref>{{cite web|url=http://www.walesonline.co.uk/news/wales-news/2010/03/20/aqueduct-attracts-otters-with-a-taste-for-the-high-life-91466-26071197/|title=Aqueduct attracts otters with a taste for the high life|website=Walesonline.co.uk|date=20 March 2010}}</ref>

==Construction and maintenance==
[[File:Longden-on-Tern1.jpg|thumb|[[Thomas Telford]] designed and built the Pontcysyllte aqueduct using the experience he gained from building [[Longdon-on-Tern Aqueduct]] on the [[Shrewsbury Canal]]]]
The [[lime mortar|mortar]] used [[lime (material)|lime]], water and ox blood.<ref>[https://canalrivertrust.org.uk/enjoy-the-waterways/canal-history/canal-heritage/aqueducts "Aqueduct"], Canalrivertrust.org.uk. 23 October 2017. Retrieved 1 May 2018.</ref> Blood and extracts of blood containing haemoglobin have been used in the construction and building industry since antiquity as air entraining colloids to inexpensively strengthen mortar exposed to freeze-thaw temperature cycles.<ref name=fpo>[http://www.freepatentsonline.com/4203674.html Use of blood to entrain air in mortar]. Free Patents Online; accessed 25 November 2018.</ref>

The [[iron]] castings for the trough were produced at the nearby Plas Kynaston Foundry, Cefn Mawr, which was built by the Shrewsbury ironfounder and millwright William Hazledine in the hope of gaining the contract. The rib castings may have been made at Hazledine's original works at [[Coleham]], near Shrewsbury.<ref>{{cite book|last=Quenby|first=Ron|title=Thomas Telford's Aqueducts|year=1992|publisher=Swan Hill Press|location=Shrewsbury|isbn=1-85310-246-6|page=[https://archive.org/details/thomastelfordsaq0000quen/page/63 63]|url=https://archive.org/details/thomastelfordsaq0000quen/page/63}}</ref> The trough was made from [[flange]]d plates of cast iron, bolted together, with the joints bedded with Welsh [[flannel]] and a mixture of [[Cerussite|white lead]] and [[Swarf|iron particles]] from [[Boring (manufacturing)|boring]] waste.<ref name=cadw/>

After 25 years the white lead was replaced with ordinary tar.<ref>{{cite book|last1=Burton|first1=Anthony|title=Thomas Telford: Master Builder of Roads and Canals|date=2015|chapter=The Shropshire Surveyor|publisher=Wharncliffe |isbn=9781473864085}}</ref><ref>{{cite thesis |last=Pattison |first=Andrew |date=October 2011 |title=William Hazledine, Shropshire ironmaster and millwright: a reconstruction of his life, and his contribution to the development of engineering, 1780–1840  |type= Ph.D.|page=105 |publisher=University of Birmingham|url=http://etheses.bham.ac.uk/3358/1/Pattison12MPhil.pdf |access-date=9 August 2016}}</ref> As with Telford's Longdon-on-Tern Aqueduct, the plates are not rectangular but shaped as [[voussoir]]s, similar to those of a stone arch. There is no structural significance to their shape: it is a decorative feature only, following the lines of the stiffening plates (see below) in the castings beneath.<ref name="cadw" />

In nearby Cefn Mawr a high quartz content sandstone was discovered at the location where the new [[Cefn Druids A.F.C.|Cefn Druids]] football stadium has since been built. Known locally as 'The Rock', the sandstone was extracted and worked here into the many numerous shapes as required by the engineers. Many remnants of the workings are still visible alongside Rock Road which links Rhosymedre to [[Plas Madoc]].

The supporting arches, four for each span, are in the form of cast-iron ribs, each cast as three voussoirs with external arches cast with an un-pierced [[I-beam|web]] to give greater strength, at the cost of extra weight. Using cast iron in this way, in the same manner as the stone arch it supersedes, makes use of the material's strength in compression.<ref name="Hopkins1970">{{cite book|last=Hopkins|first=Henry James|title=A Span of Bridges: An Illustrated History|year=1970|publisher=David & Charles|location=Newton Abbot, England|isbn=0-7153-4804-3}}</ref> They also give an impression of greater solidity than would be the case were the webs pierced. This impression is enhanced by the arrangement of strips of thicker stiffening incorporated into the castings, arranged in the manner of joints between voussoirs.

Cast plates are laid transversely to form the bed of the canal trough. The trough is not fastened to the arches, but [[Lug (knob)|lugs]] are cast into the plates to fit over the rib arches to prevent movement.<ref name=cadw>{{cite web|url=http://www.rcahmw.gov.uk/HI/ENG/Heritage+of+Wales/World+Heritage+Wales/The+Aqueducts/|title=The Pontcysyllte Aqueduct|date=February 2009|publisher=The Royal Commission on the Ancient and Historical Monuments of Wales|access-date=5 June 2009|url-status=dead|archive-url=https://web.archive.org/web/20150924084958/http://www.rcahmw.gov.uk/HI/ENG/Heritage%2Bof%2BWales/World%2BHeritage%2BWales/The%2BAqueducts/|archive-date=24 September 2015|df=dmy-all}}</ref> The aqueduct was left for six months with water inside to check that it was watertight.<ref>{{cite web|url=http://www.transportheritage.com/find-heritage-locations.html?sobi2Task=sobi2Details&sobi2Id=210|title=Heritage Locations - Pontcysyllte Aqueduct|first=Green Jersey Web|last=Design|website=Transportheritage.com|access-date=26 November 2018}}</ref> A feature of a canal aqueduct, in contrast with a road or railway viaduct, is that the vertical loading stresses are virtually constant. According to [[Archimedes' principle]], the mass (weight) of a boat and its cargo on the bridge pushes an equal mass of water off the bridge.

The [[towpath]] is mounted above the water, with the inner edge carried on cast-iron pillars in the trough. This arrangement allows the water displaced by the passage of a [[narrowboat]] to flow easily under the towpath and around the boat, enabling relatively free passage. In 1831, the original wooden towpath was replaced with an iron structure cantilevered off the side of the trough but, contrary to some texts, the {{cvt|12|ft}} wide trough, extending under the towpath to allow water displacement, remains as originally built.<ref>{{cite web |title=Build an aqueduct to carry canal boats and people across the Dee valley |url=https://www.ice.org.uk/what-is-civil-engineering/what-do-civil-engineers-do/pontcysyllte-aqueduct |website=Institution of Civil Engineers. Shaping the world |publisher=Institution of Civil Engineers |access-date=27 January 2024}}</ref> Pedestrians, and the horses once used for towing, are protected from falling from the aqueduct by railings on the outside edge of the towpath, but the holes in the top flange of the other side of the trough, capable of mounting railings, were never used. The trough sides rise only about {{convert|6|in|cm|0}} above the water level, less than the depth of freeboard of an empty narrow boat, so the helmsman of the boat has no visual protection from the impression of being at the edge of an abyss. The trough of the [[Cosgrove aqueduct]] has a similar structure, although it rests on trestles rather than iron arches. It is also less impressively high.

Every five years the ends of the aqueduct are closed and a plug in one of the highest spans is opened to drain the canal water into the River Dee below, to allow inspection and maintenance of the trough.<ref>{{cite news|publisher=[[BBC News Online]]|url=http://news.bbc.co.uk/1/hi/uk/49078.stm|title=Plug pulled on historic aqueduct|date=20 January 1998|access-date=25 November 2008|quote=At midday on Tuesday, they pulled the plug and 1.5 million litres of water, enough to fill 8,000 baths, cascaded to the River Dee below.}}</ref><ref>{{cite news|publisher=BBC News Online|url=http://news.bbc.co.uk/1/hi/wales/north_east/3271665.stm|title=Birthday clean for aqueduct|date=16 November 2003|access-date=25 November 2008|quote=next Monday and Tuesday all 12,000 cubic metres – around 12,000 bath tubs – of water will be completely drained away.}}</ref>

The aqueduct was most recently closed for maintenance in mid 2024<ref>Forgrave, Andrew, [https://www.walesonline.co.uk/news/wales-news/welsh-landmark-closed-maintenance-warning-28744145 Welsh landmark closed for maintenance with warning of more to come], ''Wales Online'' (3 March 2024). Retrieved 17 September 2024.</ref> and maintenance will be resuming in January 2025 with a further full closure of the aqueduct until mid-March.<ref>[https://canalrivertrust.org.uk/notices/29083-pontcysyllte-aqueduct-trevor Pontcysyllte Aqueduct, Trevor], Canal and River Trust. Retrieved 17 September 2024.</ref>

==World Heritage Site==
The aqueduct and surrounding lands were submitted to the "tentative list" of properties being considered for [[UNESCO]] World Heritage Site status in 1999.<ref name="unesco">{{cite web|url=https://whc.unesco.org/en/tentativelists/1326/|title=Pont-Cysyllte Aqueduct|date=29 June 1999|work=Tentative Lists Database|publisher=[[UNESCO]]|access-date=25 November 2008|quote=Pont-Cysyllte Aqueduct; Date of Submission: 21 June 1999; Criteria: (i)(ii)(iv); Category: Cultural}}</ref> The aqueduct was suggested as a contender in 2005—its 200th anniversary year<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/uk_news/wales/north_east/4470534.stm |title=Aqueduct's big bicentenary party |publisher=BBC News Online |date=27 November 2005}}</ref>—and it was formally announced in 2006 that a larger proposal, covering a section of the canal from the aqueduct to [[Horseshoe Falls (Wales)|Horseshoe Falls]] would be the United Kingdom's 2008 nomination.<ref>{{cite news |url=http://news.bbc.co.uk/1/hi/wales/north_east/6037203.stm |title=Aqueduct set for heritage status |publisher=BBC News Online |date=10 October 2006}}</ref><ref>{{cite web|url=http://www.culture.gov.uk/reference_library/media_releases/2143.aspx|title=Pontcysyllte Aqueduct And Canal – 'Magnificent Masterpiece Of The Canal Age' – To Be UK's Next Bid For World Heritage Status|date=11 January 2008|access-date=25 November 2008|publisher=[[Department for Culture, Media and Sport]]|quote=It consists of 11 miles (18 kilometres) of continuous waterway, from [[Horseshoe Falls (Wales)|Horseshoe Falls]] near [[Llangollen]] to Gledrid Bridge near Rhoswiel|url-status=dead|archive-url=http://webarchive.nationalarchives.gov.uk/20100512154509/http://www.culture.gov.uk/reference_library/media_releases/2143.aspx|archive-date=12 May 2010|df=dmy-all}}</ref>

The length of canal from Rhoswiel, [[Shropshire]], to the Horseshoe Falls, including the main Pontcysyllte Aqueduct structure as well as the older [[Chirk Aqueduct]], were visited by assessors from UNESCO during October 2008, to analyse and confirm the site management and authenticity. The aqueduct was inscribed by UNESCO on the World Heritage List on 27 June 2009.<ref name="bwb-nine-months">{{cite web|url=http://news.bbc.co.uk/1/hi/wales/north_east/8115190.stm|title=Aqueduct crowned 'world wonder'|date=27 June 2009|publisher=BBC News Online}}</ref>

==Gallery==
<gallery>
File:WalesC0171.JPG|A view of the Dee Valley from the aqueduct
File:Under Pontcysyllte.jpg|From the river and valley
File:Draining Pontcysyllte, Aqueduct - geograph.org.uk - 1579222.jpg|The canal being drained for inspection and maintenance (2009)
File:Trevor aquaduct BWver.jpg|Pontcysyllte Aqueduct in Winter
File:Aqueduct over the Dee called Pont y Cyssyltau.jpeg
File:Pontcysyllte Aqueduct and Cefn Mawr viaduct.jpg|alt=Aqueduct viewed with Pont Cysyllte bridge and Cefn Mawr Viaduct|Aqueduct viewed with [[Pont Cysyllte]] bridge and [[Cefn Mawr Viaduct]]
File:Pontcysyllte Aqueduct from above 01.jpg|alt=Aerial view|Aerial view
File:Pontcysyllte Aqueduct showing basin and football ground.jpg|alt=Aerial view showing football ground and Cefn Mawr|Aerial view showing football ground and Cefn Mawr
File:Pontcysyllte Aqueduct aerial view.jpg|alt=Aerial view|Aerial view
File:Aqueduct viewed from below - July 2021.jpg|Pontcysyllte Aqueduct viewed from below at its northern end
</gallery>

==See also==
{{Portal|United Kingdom|Transport}}
* [[Canals of the United Kingdom]]
* [[List of canal aqueducts in Great Britain]]
* [[List of bridges in Wales]]
* [[List of Scheduled Monuments in Wrexham]]
* [[Archaeology of Wales]]

==References==
{{Reflist}}

==Bibliograpy==
{{Refbegin}}
*{{Cite book 
  |first=Charles |last=Hadfield 
  |title=The Canals of the West Midlands 
  |publisher=David and Charles 
  |year=1985 
  |isbn=978-0-7153-8644-6
 }}
{{Refend}}

==Further reading==
* ''Memories of Pontcysyllte'' by Amy Douglas and Fiona Collins (2006)
* ''Pontcysyllte Aqueduct and Canal Nomination as a World Heritage Site: Nomination Document'' (Wrexham County Borough Council and the Royal Commission on the Ancient and Historical Monuments of Wales, 2008)
* ''The Shropshire Union Canal: from the Mersey to the Midlands and Mid-Wales'' by Peter Brown (2018), published by The Railway and Canal Historical Society

== External links ==
{{Commons category|Pontcysyllte Aqueduct}}
* [http://www.pontcysyllte-aqueduct.co.uk/ The Pontcysyllte Aqueduct website]
* [http://www.bbc.co.uk/shropshire/content/panoramas/pontcysyllte_aqueduct_360.shtml 360 Degree panoramic view at BBC Shropshire] (Java Applet Required)
* [https://web.archive.org/web/20070103114045/http://www.wrexham.gov.uk/english/leisure_tourism/Wrexham_Tour/Content/aqueduct_still.htm Wrexham on-line tour: Pontcysyllte Aqueduct]
* [http://vimeo.com/2267361 Construction visualisation video]
* [https://web.archive.org/web/20120218161049/http://www.rcahmw.gov.uk/HI/ENG/Heritage+of+Wales/World+Heritage+Wales/ Articles on the construction of the Pontcysyllte Aqueduct from the Royal Commission on Ancient and Historical Monuments of Wales ]
* [http://www.wrexham.gov.uk/assets/pdfs/heritage/aqueduct/management_plan.pdf Management plan for the nomination as a World Heritage Site. Includes detailed description on the scope of the World Heritage site which starts at Rhoswiel and goes through to the Horseshoe Falls ]

{{World Heritage Sites in the United Kingdom}}
{{Archaeology of Wales}}
{{Wrexham}}
{{Authority control}}

[[Category:Bridges completed in 1805]]
[[Category:Canals in Wales]]
[[Category:Grade I listed bridges in Wales]]
[[Category:Grade I listed buildings in Wrexham County Borough]]
[[Category:Bridges in Wrexham County Borough]]
[[Category:Bridges by Thomas Telford]]
[[Category:Landmarks in Wales]]
[[Category:Llangollen Canal]]
[[Category:National Transport Trust Red Wheel sites]]
[[Category:World Heritage Sites in Wales]]
[[Category:Navigable aqueducts in Wales]]
[[Category:Tourist attractions in Wrexham County Borough]]
[[Category:Bridges across the River Dee, Wales]]
[[Category:Grade I listed canals]]
[[Category:1805 establishments in Wales]]
[[Category:Cast iron aqueducts]]