Wortley Top Forge is a Scheduled Ancient Monument (Grade I) that celebrates the history of ironworking in Britain and especially in South Yorkshire. The Forge is the only surviving water-powered heavy wrought iron forge with its water wheels and hammers (now restored) in situ. It is a site of national importance.

The Industrial Revolution is usually associated with steam power. Wortley Top Forge certainly contributed both in the technology of iron making and in supporting the early Railway Age, but only ever used the strength of its three water wheels.
The Don Valley was an ideal area for iron-making as it had access to ironstone from the Tankersley seam, coppiced timber for charcoal, and water power. Iron has been working in the valley since the 1300s. Top Forge was built before 1640, deliberately in a loop of the river Don to shorten the course of the head got and to maximize the head of water available between the weir and the tail goyt.

Built by Sir Francis Wortley, the Forge was leased after the Civil War by the Spencer syndicate of Cannon Hall and dominated the iron industry in South Yorkshire for the next 100 years. In 1713, the Forge was extended by Matthew Wilson, who was managing five works, including Low Forge, on this stretch of river for his Spencer in-laws. In the the1740s, Matthew’s nephew John Cockshutt added the Tin Mill down the river. From the 1760s, his son John Cockshutt II made innovative changes, taking out patents and building Forge’s original air pump in 1770. A second son, James Cockshutt was early mentored by John Smeaton, the celebrated civil engineer (who later sponsored his Fellowship of the Royal Society). James spent time in Wales and partnership with Richard Crawshay at Cyfarthfa Works near Merthyr Tydfil; they were responsible for introducing Henry Cort’s puddling process for converting pig iron into wrought iron. In the 1790s James returned to manage Wortley Forges and was to introduce Cort’s process at Low Forge – the first site in England.