Pontcysyllte Aqueduct is generally regarded as one of Thomas Telford's greatest civil engineering achievements. Its construction was revolutionary at the time for, apart from its dramatic size and setting, Telford, rejecting all precedents, designed a cast iron trough 3.25 meters wide and 307 meters long laid along the top of 18 stone piers to carry the waterway 37 meters above the River Dee. The first stone was laid in July 1795 and construction took ten years at a total cost of £47,018