The mound stretches 34 metres from north to south and 11 metres east to west, and it is not flat. It rises gradually, standing 2.5 metres high at its northern end and climbing to 3.5 metres at the south, giving it a subtle, deliberate lean that is easy to miss until you measure it.

Ringing the mound is an earthwork arrangement that archaeologists describe in terms of a bank, an inner fosse, and an outer fosse. A fosse is simply a ditch, and the combination of a raised bank flanked by two such ditches is a feature associated with a range of early medieval and later construction traditions in Ireland, from burial monuments to enclosures around settlements or places of ritual significance. On the southern side, the line of the inner fosse is marked by a berm, a narrow flat shelf of ground left between the ditch and the mound itself. The outer fosse is roughly half a metre deep and one and a half metres wide; the bank between them rises only about half a metre above the surrounding ground. None of these are dramatic figures, but taken together they describe a structured, layered enclosure that someone went to considerable trouble to build. What exactly it was built for remains, at present, an open question.