Prehistoric copper mines on the eastern shore of Lough Leane, excavated by William O'Brien between 1993 and 1995. Mineralized exposures of limestone were exploited between 2400 and 2000 bc. Cave‐like adits have been cut into the hillslope, and there is evidence that fire‐setting had been used to weaken the rock. Abundant stone hammers were found in the adits and had been used to crush the extracted rock in order to obtain fragments of copper ore. Ore smelting using pit furnaces was undertaken at a nearby settlement, where the remains of the industrial work was associated with Beaker pottery. The arsenic‐rich ores from Ross Island supplied metal for the production of copper and bronze artefacts in the Knocknagur and Killaha industrial phases of the Irish early Bronze Age.
W. O'Brien, 2005, Ross Island: mining and society in early Bronze Age Ireland. Galway: National University of Ireland