Cyfarthfa Works was for a generation at the beginning of the 19th century the largest ironworks in the world. It was the source of the great wealth amassed by the family who owned it; the Crawshays of Cyfarthfa Castle.

The Cyfarthfa ironworks was originally founded by Anthony Bacon in 1766, and was taken over by the Crawshay family in 1786. Ironworkers produced iron that was made into weapons such as cannon, which were in great demand during the late 18th century. So important was the works to the success of the British navy that even the famous Admiral Lord Nelson visited the works in 1802. The manufacture of weapons was so strongly linked to the success of the works that the Crawshays included a pile of cannon balls in their family crest.

Such was the success of the works Richard Crawshay, the first Crawshay to run Cyfarthfa died with a fortune of 1.5 million pounds in 1810.

By the second quarter of the 19th century, the rival ironworks at Dowlais caught up with and eventually eclipsed the Cyfarthfa works. The early Victorian age witnessed these two great rivals producing enormous quantities of iron to make rails for the rapidly expanding railway networks in Britain, Europe, America and the colonies of the British Empire.

By the 1870's it was clear that the future of Merthyr Tydfil's ironworks could only continue by investing in the latest technologies and converting to steel production. Unfortunately, unlike the Dowlais Works, Cyfarthfa's switch to steel making by 1884 after a prolonged period of closure came much too late to save its former leading position amongst Merthyr Tydfil's ironworks.

The end for the Cyfarthfa works finally came in 1919 after making steel for shell cases used in the First World War. Much of the works was demolished over the course of the 20th century after it fell out of use.

The remains

The impressive remains that can still be seen are of six massive blast furnaces. A massive brick arch, which is still standing, was built to bridge the gap in the bank of furnaces. It is a sobering thought however to consider that these are just a small part of the extensive works that originally occupied this site.