What was once a rath, the Irish term for a ringfort, a type of enclosed farmstead built from the early medieval period onwards, now survives only as a faint swell in the grassland: an earthen bank worn down to little more than a low scarp, and a surrounding fosse, or ditch, that has been almost entirely filled in along its eastern arc.

The monument measures roughly 37 metres across at its widest, which places it within the typical range for this class of site. Ringforts were the dominant settlement form in early medieval Ireland, used by farming families as enclosed homesteads, with the bank and fosse serving as much for demarcating status and territory as for any serious defensive purpose. At Monkstown, the entrance gap survives on the north-east side, still measurable at 2.1 metres wide, and the interior slopes gently towards the south-east. Running across that interior, faint traces of cultivation ridges can still be made out, oriented roughly north-east to south-west, suggesting the enclosed space was put to agricultural use at some point after the fort's original function had lapsed. The site sits on a south-east facing slope with open views to the west and north-north-east, a positioning that would have been deliberate, offering both aspect and outlook to whoever once lived here.

The earthworks are low and easily overlooked, and without knowing what to look for, a visitor might walk the perimeter without fully registering the shape beneath their feet. The cultivation ridges inside are subtle; early morning or late afternoon light, when shadows fall at a low angle across the ground, tends to make such surface features most legible.