The fosse, the defensive ditch that rings the outside of this earthwork, has a clear break to the south-east, suggesting that is where people once passed in and out. But the enclosing bank directly above shows no corresponding gap. The entrance, in other words, is visible in the negative space of the ditch but has left no obvious trace in the earthwork itself, a quiet anomaly that survives in the landscape long after whoever built the place is forgotten.

This is a rath, the Irish term for a type of ringfort, the most common field monument in Ireland. Ringforts were typically farmsteads of the early medieval period, roughly the fifth to twelfth centuries, enclosed by one or more banks and ditches to define territory and protect livestock. The Rathkenny example is a substantial one. Its internal diameter measures 38 metres in both directions, making it a near-perfect circle. The earthen bank rises between 1.8 and 2.6 metres above the interior, and a full 3.6 metres above the flat-bottomed fosse outside, which is between 1.4 and 4 metres wide and sits 1.2 metres below the level of the surrounding land. That difference in scale, the bank towering over the ditch, would have made the enclosure look considerably more imposing from outside than from within. The site was recorded in the North Kerry Archaeological Survey compiled by C. Toal, published in 1995, which placed it three fields north-east of two neighbouring sites in the same townland.