Pontcysyllte Aqueduct

At Pontcysyllte, the Llangollen Canal crosses above the River Dee and one of the countries best-known canal features was built here, Telford's famous iron-trough Aqueduct. The towering arches of this aqueduct are only a few feet wider than a narrowboat and on one side the relatively thin cast-iron trough is all that separates your boat from a sheer drop down to the valley floor and the river hundreds of feet below. The length of the aqueduct sems almost impossible when you see how thin it is, and it's certainly not a time to have an attack of vertigo when standing on the roof of a narrowboat.