Ynyscedwyn ironworks was a single charcoal furnace that was believed to have been built on the site in 1612. In l823 George Crane, of Bromsgrove in Worcestershire, acquired the works and the site underwent a rapid programme of enlargement and experimentation. Crane and David Thomas applied Neilson's hot-blast method which allowed the local anthracite to be used successfully for iron smelting for the first time. This resulted in no fewer than thirty six iron furnaces being built in the
anthracite coalfield.

At Ynysgedwyn itself there were seven furnaces at the time of Crane's death in 1846 but his successors did little to develop his works. In 1866 the remaining six furnaces were largely demolished and a new charging-bank was constructed to feed two new circular metal-clad furnaces. Both of these were out of blast by 1869. In 1872 a forge or mill with monumental arches of yellow brick and a dated chimney stack were added. This project was never completed but the walls still stand. The furnace remains that were of real historical significance were cleared in 1978. Bollards cast at Ynysgedwyn survive at Swansea and at Bristol. Many of the workers were housed in the nearby College Row and in Gough Buildings. The site is associated with: Claypon's Tramroad (NPRN 34627 and Glantawe Workers' Cottages, Ystradgynlais (NPRN 25526).

Source: A Guide to the Industrial Archaeology of the Swansea Region, by Stephen Hughes and Paul Reynolds, AIA, 1989

RCAHMW, 8 September 2011.