The Pontcysyllte Aqueduct carries the Llangollen Canal over the valley of the River Dee. Completed in 1805, it is the longest and highest aqueduct in Britain, a Grade I Listed Building and a World Heritage Site.
The aqueduct was built by Thomas Telford and William Jessop and is 1,007 ft (307 m) long, 11 ft (3.4 m) wide and 5.25 ft (1.60 m) deep. It consists of a cast iron trough supported 126 ft (38 m) above the river on iron arched ribs carried on nineteen hollow masonry piers (pillars). Each span is 53 ft (16 m) wide.
The lime mortar used comprised lime, water and ox blood and the iron castings were produced at the nearby Plas Kynaston Foundry, Cefn Mawr, which was built for the purpose. The trough was made from flanged plates of cast iron, bolted together, with the joints bedded with Welsh flannel and a mixture of white lead and iron particles from boring waste.
The towpath is mounted above the water in the trough. This arrangement allows the water displaced by the passage of a narrow boat to flow easily around it, enabling free passage. Pedestrians and 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 Pontcysyllte Aqueduct is either the last point of call on our historic trip from our themed minibus tours of north wales, or last experience of our general sightseeing tour of North Wales from Chester, Liverpool or Manchester