That shed is not a later imposition on an empty field; it has been inserted into the hollow of a circular early medieval hut, its floor sitting nearly a metre below the surrounding ground level, the ancient stonework absorbed into whatever practical need came along. The mound itself, roughly 1.5 metres high and once considerably more extensive, now reads as a lumpen green rise, the dense vegetation making a full inspection difficult.

The site at Killelton is one of those places where several layers of early Christian activity have accumulated on top of one another and become almost inseparable. The circular hut is of drystone corbelled construction, a technique in which stones are laid in overlapping courses without mortar, each ring projecting slightly inward until a roof can be closed off at the top. Its interior is 3.6 metres across and its entrance probably faced north. At least two other hut sites have been recorded nearby, along with a souterrain, which is an underground stone-lined passage typically associated with early medieval settlement and possibly used for storage or refuge, and a number of quern stones used for grinding grain. A calluragh, meaning an unconsecrated or children's burial ground, occupies part of the site as well, a category of burial place found across Ireland and associated with infants or the unbaptised. Near the centre of the mound stands Clochnacrusha, also known as Cloch na Croise, a stone 1.25 metres high with a large, deeply carved Latin cross on its east face, now set into a modern base. Three hundred metres to the south-east lies Killelton oratory, which gives the whole clustering of remains a coherent early ecclesiastical character, even if the precise chronology connecting each element is not easily untangled. Hickson noted the site as early as 1889, and Hayward included it in his account of 1976, by which point the mound had already shrunk from the extent shown on the second edition Ordnance Survey map.