Remains of Iron Furnace at Cwmaman

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Ancient Monument.

The monument consists of the remains of an iron furnace dating to the industrial period. It is situated on the south bank of the River Aman, in a sheltered valley immediately below the present Town Institute.

The Cwmaman Iron Furnace is of great historical interest; a rare example of an early charcoal blast furnace from the Tudor period. It is quite likely that the development of the furnace is directly related to the origins of the present town. Even early furnaces required significant human as well as natural resources and will have attracted nearby permanent settlement. At this early date ore and charcoal will have been imported by packhorse and the iron produced exported to local forges in a similar fashion.

The early blast furnace was a large and complex structure, dependent upon water-powered bellows. It differed drastically from all previous forms of bloomery (hand, foot and water-powered bloomery) in being a continuous process, its product being entirely in the form of molten cast iron which was run out into casting beds without interrupting the operation of the furnace. A blast furnace was often in continuous operation over periods of months - and required much investment, not only in the original complex structure, but also in sufficient supplies of iron ore and charcoal and in a sufficiently sophisticated and reliable water-power facility. Round-the-clock operation also required larger numbers of workers. The whole operation was normally set up by a major secular landowner or by the Crown (which had a strategic interest in the cast-iron cannon and shot that blast furnaces could produce).

The remains of Cwmaman Iron Furnace are ruinous, the most obvious feature being part of the upstanding structure of the furnace itself. This survives within the collapsed debris from the remainder of the structure and appears as a grass and scrub covered stony mound (although with a clearly visible kiln bowl). However, other buried features are known to exist and mounds around the furnace may represent the remains of other structures or slag and cinder debris, the latter of interest in their own right to the history of metallurgy. The subterranean entrance to what is probably the leat that supplied the water wheel that powered the bellows has been uncovered immediated to the NE.

The monument is of national importance for its potential to enhance and illustrate our knowledge and understanding of the development of the iron industry in Wales. It retains significant archaeological potential, with the strong possibility of the presence of associated archaeological features and deposits. A blast furnace may be part of a larger cluster of industrial monuments and their importance can further enhanced by their group value.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.