Lothian Bridge is a lofty five-arch masonry viaduct which carries the A68 Trunk Road over the Tyne Water a quarter-mile (0.5 km) northwest of Pathhead. Built 1827-31, this impressive structure was the work of Thomas Telford (1757 - 1834) on his turnpike road between Dalkeith and Greenlaw. It is rather similar in design to his contemporaneous Dean Bridge in Edinburgh. The bridge was Category-A listed in 1971. Extending to around 120m (390 feet) in length and reaching 27.5m (90 feet) in height, it was constructed of sandstone ashlar at a cost of £8500 and features massive flaring buttresses. While the main arches are semi-circular, footpaths on either side of the bridge are supported on shallower supplementary segmental arches, an architectural device used by Telford which was intended to give the bridge a less massive appearance. The foundations proved a challenge; the sediment in the valley proved to be of such depth that the bridge could not be built on bedrock and buried platforms of logs and stone were used.