The site at Campstown is a rath, the Irish term for a ringfort, which was the most common form of rural habitation in early medieval Ireland. These enclosures, typically circular and defined by an earthen bank and an external ditch called a fosse, served as farmsteads and household compounds for farming families. Most were built roughly between the fifth and twelfth centuries, and tens of thousands once dotted the Irish landscape.

What makes this particular example quietly interesting is the way time and land use have worked on it from different directions at once. The interior measures approximately 38 metres east to west, a respectable size, and the raised circular platform survives reasonably well. But the enclosing bank has been heavily worn down, and the fosse, the ditch that originally ran outside the bank, can now only be traced along the western to northern arc. On the southern and south-western side, a low modern bank has been built into the natural slope outside the rath, which creates a visual illusion: it mimics the appearance of a berm, the flat shelf sometimes seen between a bank and its ditch, when in fact it is a later agricultural addition with no relationship to the original structure. The wide gap in the bank at the north-east, however, is likely genuine, and probably marks where the original entrance once stood.

Approaching from the south, the modern bank tends to dominate the eye, which can make reading the monument harder than expected. The northern arc, where the old fosse is still faintly legible, rewards a slower circuit of the perimeter.