The oval outline in the pasture at Killaghteen is a rath, the Irish term for a ringfort, the most common type of early medieval settlement in Ireland. Thousands of them survive across the country in various states of preservation, ranging from dramatic earthen ramparts to little more than a suggestion in the grass. This one falls closer to the latter end of that scale, and that is precisely what makes it worth attention.

The site was recorded by Denis Power and details were compiled for the national archaeological record. The rath takes an oval form, measuring roughly 21 metres north to south and 24 metres east to west, and is enclosed by an earthen bank that stands only about 0.4 metres high on both its inner and outer faces. Around the south-west to north-east arc runs an external fosse, which is simply a ditch dug to provide material for the bank and to reinforce the sense of enclosure; here it survives to a depth of 0.3 metres and a width of just under two metres. The bank itself has a very gradual internal profile, spreading to nearly four metres in width, which suggests considerable age and long, slow erosion rather than any deliberate dismantling. A probable entrance lies at the south-east, where the interior ground surface dips down toward the lowest section of the bank, a typical arrangement in raths of this type. The interior is level, sitting on a slight east-facing slope, and is currently under rough, marshy pasture.

The site sits in working farmland, so access depends on the goodwill of the landowner and the seasonal state of the ground. The marshy condition of the interior means that drier months will make for easier going underfoot. Because the earthen features are so low-lying, the rath reads best in conditions that create strong shadows across the ground, early morning or late afternoon light in spring or autumn, when the slight ridges and hollows become legible as a coherent shape rather than simply uneven grazing land. The fosse arc is the feature most likely to catch the eye first, running around the outer edge of the enclosure where the ground drops away in a shallow curve.