From Coalport to the iron bridge, the river passes through the most extraordinary district in the world. So Charles Hulbert described the Severn Gorge in Shropshire in 1837. The iron bridge built by Abraham Darby in 1779 has come to be regarded as a symbol of the industrial revolution. Now the area is a museum, winner of the 1977 Museum of the Year Award. Paul Vaughan spent a day at Ironbridge Gorge Museum.