The apparent cave is in fact the entrance to the main tomb, a short passage just over three metres long, roofed with slabs, leading into a chamber roughly two metres across with three shallow recesses and a stone basin decorated with pecked ornament. That the people who compiled the nineteenth-century place-name books had no framework for understanding what they were looking at says something about how thoroughly the meaning of these monuments had been lost.

Excavations carried out between 1934 and 1936 by P.T. Walshe revealed that the cairn, approximately 27 metres in diameter, was not a single construction but a multiperiod monument with at least five distinct structures buried within or beneath it. A passage tomb is a type of megalithic chamber tomb in which a narrow stone-lined corridor leads to an inner chamber, typically used for collective burial. Here, the main tomb on the north side is accompanied by a second tomb to the south, its chamber divided into three compartments, with no evidence of a passage. On the north-west side are the remains of a small corbelled structure, partly covered by the inner kerb, and a fifth chamber sits to the east of the main tomb. Several stones across both the inner and outer kerbs carry passage tomb art, the abstract incised and pecked decoration, spirals, lozenges, and cup marks, associated with this tradition across Ireland and beyond. The human remains recovered were the cremations of at least three adults and one child. Alongside them were flint scrapers, bone pins, and Carrowkeel pottery, a coarse round-bottomed ware typical of Irish passage tomb assemblages. Beneath the cairn itself were even earlier deposits: a stone axe, a flint javelin-head, carbonised wheat grains, hazelnuts, an egg-shaped stone, and a saddle quern used for grinding grain. The cairn material was subsequently built up into a substantial protective wall around the monument after excavation.

The site sits within the south-east sector of Rathcoran hillfort, a later prehistoric enclosure that reused and reframed a landscape already ancient by the time it was built. A second cairn lies approximately 100 metres to the south-west, suggesting this hilltop was a place of accumulated significance across many generations. The decorated kerb stones are not always easy to read in poor light, but they are there for those who look carefully.