Archaeologists who have examined it find themselves in an unusual position: the structure survives well enough to describe in some detail, but not well enough to place into any of the recognised categories of Irish prehistoric tomb. It sits in that uncomfortable space between evidence and conclusion.

What remains is a roughly angled stone structure, around three metres long and less than a metre wide, oriented approximately east-north-east to west-south-west. Two roof-stones still cover it. At the western opening, a stone has been set lengthways along the interior, dividing the entrance, and traces of the original earthen or stone mound that would once have enclosed the whole structure are still faintly visible to the west, north, and east. Megalithic tombs, a broad term for prehistoric burial monuments built from large stones, come in several distinct types in Ireland, including portal tombs, court tombs, and passage tombs, each with particular architectural signatures. This one, damaged and partial as it is, does not fit cleanly into any of them. There is a possible historical footnote: the antiquarian George Petrie, writing in 1972 in a volume drawing on earlier research, mentioned a site at Dunmore with a cromleac adjoining, a cromleac being an older term for what we would now call a dolmen or megalithic tomb, and this may refer to the An Doirín monument or to a nearby related structure. The connection remains tentative.