Nant yr Eira Prehistoric Copper Mines & 19th Century Lead Mine

Cadw's description

Summary description and reason for designation

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

The monument consists of a mine, an excavation made in the earth for the purpose of digging out metallic ores, coal, or salt. The ores at Nant yr Eira have been exploited since the Bronze Age period.

The prehistoric remains consist of a deep open-cut working in the rock. Trial excavations have produced stone mining tools, ore, charcoal, and radio carbon determinations confirming a Bronze Age date. Mining was resumed in 1858 and continued until 1883. The remains from this later phase include a crusher house with wheel-pit, a drystone ore-bin above this, a second wheel-pit and two round buddles. There are also extensive waste heaps from this phase. The site lies beside the Nant y Eira stream, on the edge of forestry plantations.

The present scheduled area following two revisions includes the prehistoric opencast copper mine which extends for a distance of c. 90m along the present course of the stream, the 19th century lead mine complex to the south of this. To the north of the prehistoric mine a separate scheduled area includes the reservoir, stone-built dam, two adits, one trial adit and a rock cut level. The reservoir supplied water to the water wheel that powered the crusher of the lead mine.

The wheel-pit and crusher house are the most visible and most easily identified structures of the mine complex but also visible are other features including a second wheel-pit which contained the wheel that presumably powered the jiggers to the SE. To the SE of the crusher house are the collapsed low stone walls of a square building which may have been either the mine office or a smithy. There are also two ore bins to the NW of the crusher house and a buddle to the SW. The main shaft and a large waste tip lies to the NE and a raised tramway made of mine waste leads from the shaft to the ore bins. A second tramway approaches the bins from the NW. This would have transported ore from the reworked open cut. Parallel to this is a well-defined leat some 40m long which terminates some 20m above the wheel pit. Presumably water reached the wheel via a launder.

The monument is of national importance for its potential to enhance our knowledge of mining practices. It retains significant archaeological potential, with a strong probability of the presence of associated archaeological features and deposits. The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive.