Today we are in Wales, and the photos are of the magnificent 208 year old Pontcysyllte Aqueduct, which is a navigable waterway that carries the Llangollen Canal over the valley of the River Dee in North East Wales. Completed in 1805, it is the longest, and highest aqueduct in Britain, a Grade 1 listed building , and a World Heritage Site. When the bridge was built, it linked the villages of Froncysyllte, at the southern end of the bridge, with Cysyllte township of Llangollen parish (from where it takes its name).
The aqueduct was built by Thomas Telford, who was a Scottish civil engineer, noted around the British Isles for being a road, bridge and canal builder. The aqueduct 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 valley on iron arched ribs, carried on nineteen hollow masonry piers (pillars). Each span is 53 ft (16 m) wide. Despite considerable public scepticism, Telford was confident the construction method would work. It was opened on 26 November 1805, having taken around ten years to design and build at a total cost of UKL47,000. Adjusted for inflation this is equal to £2,930,000 as of 2013 ($4,400,00), and the structure is still standing, and working today – 208 year on. 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 narrow boat to flow easily under the towpath and around the boat, enabling relatively free passage. 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 6 inches (15 cm) above the water level, so the helmsman of the boat has no visual protection from the impression of being at the edge of an abyss, a very uneasy feeling for many boaters who cross the valley on the aqueduct. I have a fear of heights so as much as I could stand on one side of the bridge and admire both the structure and the wonderful view, there is no way I could walk across.