When excavators broke into the mound, they found not a simple pile of stones but a ring of eighteen stones set radially outward from a central point, like the spokes of a wheel, with their sockets still intact within a circle roughly six metres across. The cairn material itself had spread about a metre beyond that ring. What made the find stranger still was the discovery, towards the western side beneath the cairn surface, of two large stones with a curving arc of smaller stones arranged between them, and, about thirty centimetres below the cairn surface, three fragments of scallop shell. Shells this far inland, placed deliberately under a mound, sit somewhere between the mundane and the ritual without fully belonging to either.

The cairn was excavated in 1938 by Seán P. Ó Ríordáin, who published his findings the following year. It does not stand alone. The site forms part of a small prehistoric complex on a level, bog-covered shoulder of the hills, which also includes a five-stone circle and a pair of standing stones. The cairn lies roughly two metres south-east of the standing stones and five metres east of the circle. Three large, closely-set sockets arranged in a trench along a north-east to south-west alignment were uncovered on the north-west perimeter of the cairn, though their original purpose remains unclear. Five-stone circles are a distinctive Cork and Kerry monument type, typically consisting of four upright stones flanking a recumbent, or horizontal, stone, and they are often found in association with other prehistoric features, as they are here. The grouping at Maughanaclea represents one of the more complete examples of this kind of compound arrangement in the region.