Yet the arrangement at Carrownakib, sitting on a low knoll about 1.2 kilometres from the eastern shore of Lough Corrib, represents the heavily weathered remains of a court tomb, one of Ireland's oldest monument types, built by Neolithic farming communities perhaps five or six thousand years ago. Court tombs take their name from the open, usually semicircular forecourt that funnels mourners or ritual participants towards the burial gallery. Here, the court has been reduced to a single flanking courtstone beside the northern entrance jamb, with a second stone in a corresponding position on the south side that may once have served the same purpose.

What survives of the gallery stretches roughly 5.5 metres along an east to west axis, defined by two entrance jambs at the east end, two sidestones along the northern wall, and a backstone closing the western end. The overall dimensions suggest the gallery originally held at least two chambers, divided by septal stones set between opposing sidestones. The whole structure sits within a subrectangular earthen mound measuring approximately 12.5 metres long and 10 metres wide, though the monument is described by researchers, including Ruaidhrí de Valera and Seán Ó Nualláin in their 1972 survey of megalithic tombs in Connacht and the midlands, as very ruined. What makes the location quietly unusual is its immediate neighbourhood: roughly 130 metres to the north-west lies a separate, unclassified megalithic tomb, and about 160 metres to the north-north-west there is an anomalous group of stones whose relationship to the court tomb remains unclear. Three distinct prehistoric stone monuments within a few hundred metres of one another in open pasture suggests this gentle knoll was considered a significant place long before the land around it was given over to grazing.