Iron Bridge, Ironbridge, Shropshire, c1955-c1980. A general view of the Iron Bridge, a single-span arched bridge over the River Severn built in 1778. Designed by Thomas Farnolls Pritchard and built by Abraham Darby III at his foundry in Coalbrokdale, it was the first bridge to be constructed using Darby's new method of smelting cast iron. The view shows the underside of the arch and the southern piers.