Ironbridge

Ironbridge, Coalbrookdale, the revolutionary iron bridge over the River Severn in Coalbrookdale, Shropshire, west-central England, designed by Thomas Pritchard and built by the ironfounders John Wilkinson and Abraham Darby in 1777-1779. It takes the form of a five-ribbed semicircular arch spanning a width of 43 m (140 ft); each of the ribs was cast in two halves. The first cast-iron bridge to be successfully erected, and the first large cast-iron structure of the industrial age, it led in the 19th century to such feats of architecture as the ambitious vaulting of London's Paddington Station and the construction of Crystal Palace.

The old industrial sites around Ironbridge fell into decay and dereliction in the 19th century but have in recent years been developed by the Ironbridge Gorge Museum Trust; they now form a display of industrial archaeology that constitutes the largest museum in Britain. Ironbridge itself, which is open only to pedestrians, is now a national monument, and, since 1986, a UNESCO World Heritage Site.