It sits on the summit of a drumlin, one of the rounded glacially deposited hills that give this part of Ireland its characteristically lumpy, rolling landscape, and its elevated position would once have made it an effective lookout point as well as an enclosure for livestock or a homestead.

A rath, as this type of earthwork is known, is a roughly circular enclosure defined by an earthen bank and a fosse, which is simply a surrounding ditch, the soil from which was typically thrown inward to build up the bank. They are among the most common archaeological monument types in Ireland, most dating from the early medieval period, roughly the fifth to the twelfth centuries, and were used primarily as defended farmsteads. The Campstown example has an internal diameter of approximately 29.2 metres, a reasonably substantial size. Its perimeter from the eastern side running south and around to the west-southwest has been absorbed into the existing field boundary, meaning that farmers at some point found the bank more useful as a convenient ready-made field division than as an archaeological feature to preserve. Elsewhere the earthwork has been largely levelled, though its outline can still be traced on the ground.

The absence of any Ordnance Survey marking across all map editions suggests the site was either overlooked during the original surveys or had already been significantly reduced by the time surveyors passed through. What remains is a faint but legible impression in the landscape, most readable from close inspection of the hilltop itself, where the curve of the surviving bank and the logic of the incorporated field boundary reveal the original shape of a place where someone, more than a thousand years ago, chose to build their life on the highest point available to them.