Tallest navigable canal aqueduct

The world's tallest navigable canal aqueduct is the 38.4-m-tall (126-ft) Pontcysyllte Aqueduct, which was built in 1805 to carry the Ellesmere Canal across the River Dee around 5.5 km (3.4 mi) east of Llangollen in Wales, UK.

The Pontcysyllte Aqueduct was designed by civil engineer, architect and occasional poet Thomas Telford – whose contributions to British infrastructure earned him the nickname "The Colossus of Roads".

Telford was a pioneer in the use of cast iron for major engineering projects, and made use of this still fairly novel construction method to build several canal aqueducts. The Pontcysyllte aqueduct consists of 18 stone piers topped with a 307-m-long (1,007-ft) cast iron trough. The spans between piers are supported by cast iron arches.