It was sitting at the edge of a reservoir, periodically submerged, preserved by a layer of sand that had been quietly washing away. When Christopher J. Darby spotted it on the shoreline of the Poulaphuca Reservoir at Carrigacurra, Ballyknockan, in March 2010, the site had only just become visible, most likely because high water levels in 2009 had stripped away the sand that had been shielding it. The western and southern sides were already eroding. A rescue excavation followed, directed by archaeologist Chris Corlett under licence 10E0131.

What Corlett uncovered was a wedge tomb, a type of megalithic burial monument typically associated with the early Bronze Age, characterised by a narrow, wedge-shaped stone chamber that is wider and taller at one end and open at the front. The chamber at Carrigacurra measured 1.2 metres long and 0.45 metres wide, formed from two large slabs on the southern side, three on the northern, and two end stones, all set off-centre within a U-shaped kerb arrangement retaining cairn material. The nearest comparable monument sits at Sroughan, roughly 5.5 kilometres to the north. No dating evidence for the original construction was recovered, though the excavators noted that material beneath the undisturbed cairn and kerb might still hold answers. What the excavation did reveal clearly was a second phase of activity, datable to the early Iron Age. A dense, deliberately placed layer of charcoal, 50 millimetres thick and identified by specialist Ellen O'Carroll as hazel and oak, had been carefully laid within the chamber and extended beyond it to the north and east. Radiocarbon dating of hazel samples returned a date of 760 to 414 BC. There was no evidence of burning in place; the charcoal was brought here. After it was deposited, three stones were placed on top of it and the chamber was reduced in size, suggesting the space was being reconfigured, possibly for renewed use as a burial site. Whether any burial actually took place cannot now be determined. The reservoir has seen to that.