It is not a rath in the usual sense, though it sits directly attached to one. Instead it forms a kind of annex, a grass-covered arc roughly forty metres from north to south and seven and a half metres wide, defined by an earthen bank along its southern edge and a low scarp running from the south-west around to the north.

A rath, for those unfamiliar with the term, is a roughly circular earthen enclosure, typically of early medieval Irish date, built as a farmstead and defined by one or more banks and ditches. What makes this site at Cloonteem worth noticing is precisely what it is not: it lacks the closed circular form of the rath it adjoins, and its crescent shape, pressed against the south-western side of that larger enclosure, suggests it served a subsidiary function. Annexes of this kind were sometimes used to pen livestock, to provide additional sheltered ground, or to extend the usable area of a settlement without the labour of constructing a full second enclosure. The earthen bank here measures about three and a half metres wide but only around thirty centimetres high, and the scarp along the rest of the perimeter rises no more than half a metre, so the whole thing sits very close to the level of the surrounding field. That proximity to the Shannon to the west would have made this a particularly useful position for any community dependent on the river, whether for fishing, transport, or simply the reliable presence of water.