The Aqueduct carries the Llangollen Canal over a valley in which runs the River Dee. Completed in 1805 it is the longest and highest Aqueduct in the United Kingdom.
It was built by Thomas Telford and William Jessop and is 307m long 3.7m wide and consists of a cast iron trough supported on eighteen masonry pillars with 16m spans 38m above the river.
Originally the aqueduct was part of the Ellesmere Canal and the work was undertaken by Telford under the supervision of Jessop. The iron was supplied by William Hazledine from his foundries in Shrewsbury and Cefn Mawr. It opened on 26 November 1805 having taken some ten years to design and build at a cost of £47,000.