The structure is a rath, the most common type of ringfort found across Ireland, essentially a circular enclosure defined by raised earthen banks and a ditch, used as a farmstead and place of security during the early medieval period, roughly the fifth to twelfth centuries. This particular example measures around 29 metres in diameter and retains the outline of two banks with an intervening fosse, the shallow trench between them, though the whole is described as poorly preserved.

The ringfort lies within the former Clonbrock demesne, the landed estate that was associated with the Dillon family, who held considerable influence in County Galway. The gentle north-northeast-facing slope on which it sits would have been unremarkable farmland long before any grand estate was laid out around it, and the earthwork itself predates the demesne by many centuries. That an early medieval enclosure survived at all beneath the later landscaping of an estate is not unusual in Ireland, where such features were often left undisturbed out of a mixture of superstition and simple inconvenience, ringforts being difficult to level completely and widely associated in folklore with the otherworld.