Known locally as Cnoc Raithní, the mound is a substantial thing, some 21 metres across and rising to more than 1.5 metres, its circumference held in place by a drystone revetment wall. The flat top is divided in a way that makes the monument feel quietly composite: the southern half shows the edges of slab-lined graves still protruding above the surface, while the northern half carries a small rectangular kerbed platform, just under a metre high, topped with two modest limestone pillars. What exactly the platform represents, and how it relates to the graves beside it, is not entirely resolved.

The mound came to light in 1885 when shifting sands exposed it, as dunes on Atlantic islands have a habit of doing, revealing and concealing things on their own schedule. The Board of Works moved in to excavate and restore the site, though the quotation marks that tend to surround those words in the literature hint at the uncertain standards of the time. What was recovered from a stone-lined cist, a small box-like burial chamber formed from upright slabs and a capstone, included a cordoned urn, a second smaller vessel, a bronze artefact, and bone. Cordoned urns are a Middle Bronze Age ceramic type, typically dating to somewhere in the second millennium BC, used in funerary contexts across Ireland and Britain. Other graves and further pottery were found during the same intervention, but the record of where exactly these were located and how they related to one another became muddled, a confusion that later researchers noted and were unable to fully untangle.

The mound sits close to the shore and is accessible on foot from the island's small pier. Inis Oírr is reached by ferry from Doolin in County Clare or from Ros a' Mhíl in Galway, and the island is compact enough that most of its monuments are within easy walking distance of one another. The low limestone pillars on the platform are easy to overlook, but they are worth pausing over, sitting as they do above centuries of accumulated disturbance, excavation, and weather, with the Atlantic just below.