It measures roughly eight metres by seven point eight metres, drops about thirty centimetres below the surrounding surface, and has a roughly sub-rectangular shape. It sits inside the southern quadrant of a ringfort, and the most that can confidently be said about it is that it may once have been a house. The date is indeterminate.

Ringforts, sometimes called raths, are enclosed farmstead sites typically dating from the early medieval period in Ireland, roughly the sixth to the twelfth centuries, though some are earlier or later. They are among the most common archaeological monument types in the Irish landscape, yet the activity that took place inside them is often poorly understood. Traces of structures within a ringfort tend to survive only as slight depressions or soil discolourations, because the buildings were generally timber or earthen rather than stone. The hollow at Kilpatrick fits that pattern: a faint indentation in the southern part of the enclosure, just legible enough to suggest that something was once built there, but not so clear as to settle the question. Its position on the north-western side of a ridge would have given its occupants, whenever they lived, an open prospect across the landscape to the north and north-west.