©Cadw: Welsh Historic Monuments

Blaenavon Ironworks

Blaenavon Ironworks is remarkable for the substantial remains of five early blast furnaces, the construction of which began in 1788-89. They were fuelled by coke and the blast was maintained by a steam engine, the chimney for which gave its name to Stack Square - the group of preserved workers' houses adjacent to the furnaces. An impressive water-balance tower - a hydraulic hoist to move heavy raw materials - also survives.

Blaenavon is famous as the site where Sidney Gilchrist Thomas developed the 'basic steel process' in 1878. This process transformed steelmaking throughout the world by allowing high phosphorous ores to be successfully exploited.

Blaenavon Ironworks is part of the Blaenavon Industrial Landscape, which was designated a World Heritage Site in 2000.