What survives is a raised oval platform, measuring roughly 37 metres north-northeast to south-southwest and 32 metres across its other axis, the kind of modest but deliberate shaping of the earth that speaks to a community that once lived, worked, and defended itself here.

This is a rath, the Irish term for a ringfort, which was the most common form of rural settlement in early medieval Ireland, broadly from the fifth to the twelfth centuries. A typical rath consisted of a circular or oval enclosure defined by one or more earthen banks with accompanying ditches, known as fosses, dug to provide both the material for the banks and an additional obstacle to anyone approaching. At Keilagh, the remains suggest a bivallate design, meaning two concentric banks each fronted by a fosse, which would have offered a more substantial barrier than the single-bank examples found elsewhere. The original entrance appears to have faced south, a common orientation in Irish ringforts, possibly for practical reasons related to sunlight and prevailing weather. Much of the earthwork has been damaged over time; the inner bank and fosse have been largely levelled, as has a significant stretch of the outer circuit running from the north around to the south-southwest, leaving only partial traces of what was once a complete enclosure.