It is a rath, a type of ringfort constructed from a raised earthen bank enclosing a roughly circular area, and for much of early medieval Ireland these were the basic unit of rural settlement, the farmsteads of farmers, minor lords, and everyone in between. This one measures twenty-five metres in diameter, defined by an earthen bank rising to about one and a third metres, with an entrance facing north-north-east.

Thousands of ringforts survive across Ireland, though many have been ploughed out, built over, or simply eroded into invisibility. They date broadly from the early medieval period, roughly the fifth to the twelfth centuries, and would typically have enclosed a house or small cluster of buildings, with the bank serving as much as a boundary marker and enclosure for livestock as any serious defensive structure. The Barrahaurin example is modest in scale, as many are, and its setting in the Dripsey valley places it in a landscape that would have supported exactly the kind of small-scale pastoral farming these enclosures were built around.