Because the ground falls away beneath it, the interior was deliberately raised on the south-east side to create a level living floor, a small but telling detail that speaks to the care taken in laying out what was once, most likely, a defended farmstead.

The site is a rath, the commonest monument type in the Irish landscape. Raths are ringforts built from earth rather than stone, and they date in the main to the early medieval period, roughly the fifth to twelfth centuries, when they served as enclosed farmsteads for farming families of middling rank. This one is a substantial example: the roughly circular enclosure measures nearly sixty metres across, surrounded by an earthen bank still standing close to two metres high. On the west and north-west sides, an external fosse, a defensive ditch, adds further definition; it survives to a depth of around 1.2 metres. An entrance gap opens to the south-east. What makes the setting particularly layered is the presence, just ten metres to the north-east in an adjoining field, of two long cists. Long cists are stone-lined grave boxes, typically associated with early Christian burial practice, and their proximity to the ringfort suggests that this corner of Killavarrig was a focus of activity across more than one phase of the early medieval period, or perhaps that the dead were kept deliberately close to the living.