Its enclosed interior is sub-rectangular, stretching approximately 44 metres north to south and 37 metres east to west, which sets it apart from the more typical round or oval examples scattered across the Irish countryside.

A ringfort, or rath, is an early medieval enclosed settlement, usually dating from roughly the fifth to the twelfth century, in which a bank and ditch were thrown up around a farmstead to define territory and offer a degree of protection. At Kyleballynamoe, the earthwork is substantial by any measure. The enclosing bank runs to an overall width of ten metres, narrowing to two metres at its crest, and stands roughly 1.5 metres above the interior ground level and 2.3 metres above the exterior. Beyond the bank lies a wide, flat-bottomed external fosse, a defensive ditch, measuring four metres across and 1.3 metres deep. These dimensions survive best on the southern and western sides. To the east, both bank and fosse have been reduced to little more than traces, and along the northern side only a scarp, a pronounced slope in the ground, remains to suggest where the original earthwork once ran. The slight hillock on which the fort sits places it just at the point where the valley side meets the valley floor, giving the interior a clear sightline along and across the Nuenna valley, which would have made practical sense for anyone keeping watch over the surrounding land.

The most visible modern intrusion is a tractor ramp cut into the northern side, which now serves as the practical entrance to the interior. The surrounding land is given over to grass and tillage, and the earthwork sits within that working agricultural context rather than being set apart from it, which gives some sense of how continuously this particular corner of Kilkenny has been farmed across the centuries.