That combination, a defensible elevation ringed by boggy terrain, is exactly what you would want if you were building an enclosed settlement and hoping the landscape itself would do some of the defensive work for you. The enclosure is roughly circular, about 78 metres across, and its defining features are a bank and a fosse, the fosse being the external ditch that accompanies the bank and adds to its effective height. Measured from the bottom of the ditch, the bank rises about 1.4 metres on the outer face, dropping to around 0.8 metres internally, with the whole earthwork spanning about 5 metres in width.

The enclosure was already old enough to be mapped when the first edition of the Ordnance Survey six-inch sheets was produced in 1839, and that early map records it as a slightly irregular oval, measuring roughly 78 metres north to south and 86 metres east to west. A curious northward kink in the northern sector is visible on the ground today, and it is likely explained by a small quarry that would have cut into and displaced part of the original line. What is perhaps equally telling, in a quiet administrative way, is the route of the local townland boundary: rather than cutting across the monument, it bends to follow the southern arc of the bank, suggesting that the earthwork was already a fixed and respected landmark when those boundaries were laid out, and that communities organised their land around it rather than through it.