It appears on the 1925 edition of the Ordnance Survey six-inch map but not on earlier editions, which says less about when it was built than about how long it went unrecorded. The enclosure measures around 33 to 34 metres in diameter, and what makes it particularly interesting to anyone who takes the time to read the ground carefully is the layering of its defences: an inner earthen bank, a surrounding fosse or ditch, a berm separating that ditch from a slight outer bank, and beyond that a second outer fosse surviving along the south-southwest to west-northwest arc. A causeway, roughly 3.5 metres wide, carries the original entrance through both banks at the south-southwest.

Ringforts, known in Irish as raths when formed from earthworks rather than stone, were the dominant settlement type of early medieval Ireland, built roughly between the fifth and twelfth centuries. Most enclosed a single farmstead and its inhabitants, with the bank and ditch serving as much to contain livestock and signal status as to provide any serious military defence. The Kilbraney example is more elaborate than average: the combination of an inner bank, a complete fosse, a berm, an outer bank, and traces of a second outer fosse points to a site of some consequence, or at least to one that was defended in stages, possibly at different periods. The slight outer bank running northwest to northeast may be a secondary addition, suggesting the enclosure was modified or reinforced at some point after its original construction. When a gas pipeline was laid roughly 20 metres to the west of the site, archaeological monitoring of the ground in that area produced nothing directly associated with the fort, leaving its history without any datable material finds so far.