Pontcysyllte Aqueduct and Canal

With its 19 symmetrical metal arches supported by tall, slender masonry piers, Pontcysyllte Aqueduct is a marvel of 19th century engineering. But even those who don’t know their acute from their obtuse angles will be awed by the scale and elegance of the stoic monument, which still transports narrowboats on a slender stream of water some 38 metres (126ft) above the River Dee.

The structure and adjoining canal, which became a UNESCO site in 2009, is over 200 years old and was designed by celebrated civil engineer Thomas Telford. The highly ambitious project – with the aqueduct spanning the wide valley without the use of locks – is considered his first masterpiece. Telford would go on to oversee further construction projects in Wales including both the Menai and Conwy Suspension Bridges, two of the first such bridges in the world.

Along with the aqueduct, the UNESCO listing includes 17km of scenic canal way (where boats are still pulled along by horses), as well as infrastructure involved in the completion and maintenance of the project, such as engineers’ houses and canal-side wharfs.

Today, the aqueduct is a rite of passage for seasoned boaters, who brave the precipitous crossing for the panoramic vistas of the Llangollen countryside. Walkers – with a good head for heights – can also make the crossing, using the towpath that runs alongside the canal.