Copa Hill, on the north side of the Ystwyth Valley, is an area with a complex and rich mining landscape, which spans ten historic phases of mining and prospection, overlain with a more recent agricultural landscape. Evidence of medieval and post- medieval elements and traces of a former prehistoric landscape are still recognisable.

Extensive survey work and investigation was carried out from 1986 to 1999, with archaeological sampling/evaluation trenches or pits also cut at a number of different locations to provide a broader assessment of Copa Hill. A broad range of surface structures, revealed through this ground survey and aerial photography includes a complexity of linear features, mostly water channels connected with the process of hushing. Associated reservoirs and dams are also visible. Other features include mining tunnels and shafts, opencast pits, track ways and a railway incline. An embanked field with cultivation ridges lies close by on the south.

Copa Hill saw different phases of the mining: Early Bronze Age Opencast; Medieval leats, hushes, a trial adit working and lead roasting and smelting hearths along with platform houses and field banks; Post-Medieval, including the largest complex of mine workings on Copa Hill the `Roman Dumps?, through to Victorian and modern twentieth century mining found lower down on the south and west slopes of Copa Hill and include deeper shaft workings and a succession of shafts and levels and the construction of the stone bank and bridges for the self-acting incline and its associated features all add to the complexity of the site. There is also evidence for small-scale peat extraction on the top of Copa Hill with small rectangular platforms for drying platforms and ruts which suggest sledges were used to carry the peat.

Copa Hill is therefore, perhaps typical of a small-medium sized opencast trench mine which exploited impersistent but locally rich pockets of copper ore within copper-lead-zinc sulphide veins cutting the Lower Palaeozoic rocks. The earliest mining may have been commenced around 2500BC with surface collection of minerals and undercutting with fire used to excavate the rock and break up the copper ore. By 2000BC opencast mining was being carried out from the down-slope end of the trench, with the mine reaching its maximum depth about a hundred years later. Over the next two to three hundred years, following abandonment of the deeper sections of the mine due to water-logging, the mine continued to be worked upslope (northwards) on a more piecemeal basis. The mine was finally abandoned in 1600BC following continued water-logging and infill from peat and mine spoil. The finds at the mine of water-worn cobbles (since 1986, 1203 of unbroken or partially complete have been found), used as mining hammers, crushing stones and anvils is characteristic of primitive prehistoric mine, and with few other identifiable remains from habitation or smelting, suggests it is typical of those mines which produce no ceramic or metalwork remains, and were seasonal in nature. The miners may have been pastoralists. The site may have produced only 1-2 tons of copper in total, which could have traded by the miners piecemeal as ore concentrate rather than as refined metal.

Later Roman activity is indicated and during the 11th-12th century AD a shaft was sank into the opencast, probably abandoned shortly afterwards. A leat was constructed from upper Nant yr onnen to flood the in-filled opencast depression to use as a hushing pond. Hushing is likely to have either been used to excavate the earlier spoil tips on Copa Hill to recover lead or to uncover the Comet Lode down-slope, the latter on behalf of the Cistercian monks at Strata Florida. Subsequently shafts c 1730 and again in 1813 or before, shafts were sunk into the opencast and later abandoned.

Finds during the excavation include numerous wooden artefacts; three bronze age wooden launders; wooden stakes and posts, mainly from within the prehistoric levels; stemples and planks found deep within the workings and associated with the early bronze age mining; handles, wedges, fire-stick etc; withy handles, ties, rope and basketry. One complete antler pick/hammer, two large broken tine fragments plus several detached flakes or splinters were recovered from fine-grained mine sediments within the mine entrance.

This area is a Scheduled Ancient Monument (CD145)

Source: Timberlake, S (2003) Excavations on Copa Hill, Cwmystwyth (1986-1999). An Early Bronze Age copper mine within the uplands of Central Wales. BAR British Series 348, 2003