The site is a rath, the Irish term for a ringfort, which was the standard form of enclosed rural settlement in Ireland from roughly the early centuries AD through to the Norman period. Tens of thousands of them survive across the island, but this one in Killea has been worn down to something barely legible, its western and south-western arc erased by drainage work, leaving only a partial outline where there was once a complete enclosed world.

What does survive gives a reasonable sense of the original structure. The enclosure was oval, measuring about 22 metres north to south and 26 metres east to west, defined by an earthen bank, a fosse (the surrounding ditch that would have reinforced the bank with the soil dug from it), and traces of a second, outer bank to the north-north-east and east-north-east. The entrance, facing north-east, survives in both the inner and outer banks, at widths of 3.25 metres and 4 metres respectively. That double-bank arrangement, modest as the surviving earthworks are, points to a settlement that was once more elaborately defended or demarcated than a simple single-bank enclosure. A drain running roughly north to south, some 18 metres long, cuts through the western sector and is likely responsible for the unnaturally straightened scarp visible to the west-north-west. The site was identified as an enclosure through aerial photography by the Air Corps and the Geological Survey of Ireland in 1974. A second enclosure sits roughly 12 metres to the west-north-west, suggesting this was not an isolated farmstead but part of a small cluster of related activity. The interior is waterlogged at its centre, and a raised area in the north-east quadrant, possibly the remnant of a structure, is buried under dense grass.