Pontcysyllte Aqueduct and Canal – Facts and Figures
While the outstanding feature of the World Heritage Site is undoubtedly Pontcysyllte Aqueduct, the site is 11 miles (18 kilometres) long, from Gledrid Bridge near Rhoswiel to the Horseshoe Falls.
10.5 miles (17 kilometres) lie within Wales and the remaining 0.5 miles (1 kilometre) in England. Excluding the land which provides the immediate setting of the three key features (Pontcysyllte Aqueduct, Chirk Aqueduct and the Horseshoe Falls), some 95% of the site is owned by British Waterways.
UNESCO requires that both the site and its setting are protected from any development deemed harmful to the ‘Outstanding Universal Value’. To do this many World Heritage Sites have an agreed buffer zone designated around them and this is the case for Pontcysyllte Aqueduct and Canal.
The buffer zone takes in land around the Horseshoe Falls and most of the Dee Valley downstream, stretching right up to the ridgelines on both sides of the valley. The majority of this area is already designated as a special Historic Landscape area.
Where there is no longer a ridgeline as the topography changes beyond Froncysyllte, a corridor of land either side of the canal has been identified by landscape planners from the respective councils. The buffer zone is most complex at Cefn Mawr, where a combination of landscape planning and industrial archaeology has been used to draw the boundary line.
- Pontcysyllte means ‘the bridge that connects’. It created a navigable union between England and Wales, connecting the rivers Severn, Dee and Mersey.
- There are 18 piers 126ft high (38.4m) and 19 arches, each with a 45ft (13.7m) span.
- To keep the aqueduct as light as possible, the slender masonry piers are partly hollow and taper at their summit.
- The mortar was made of oxen blood, lime and water.
- The aqueduct holds 1.5 million litres of water and takes two hours to drain.
- For the non-Welsh speaker, Pontcysyllte is pronounced ‘pont-kur-suck-tay’.
- The Pontcysyllte Aqueduct is 1,007ft (306.9m)long and spans the valley from Trefor (or Trevor) to Froncysyllte, with the River Dee running beneath it.
- The work was undertaken by Thomas Telford and supervised by the more experienced canal engineer William Jessop.
- The first stone was laid in July 1795. It was completed in 1805 using local stone.
- At the centre, it reaches a height of 126ft (38.4m) from the river bed to the ironwork.
- This is the largest aqueduct in Britain. It is fed by water from the Horseshoe Falls near Llangollen.
- The water that feeds the canal runs through an iron trough that measures 11ft 10ins (3.6m) wide and 5ft 3ins (1.6m) deep.