What was once a roughly circular enclosure, somewhere in the region of 36 metres across at its longest, is now little more than a low scarp of earth, rising at most about a metre and a quarter above the surrounding ground. A ploughed furrow has cut directly across the southern half of the monument, a reminder that these earthworks have been quietly losing their definition to agricultural activity for generations.

Raths, as these enclosures are commonly known, were the typical dwelling sites of early medieval Ireland, roughly from the sixth to the twelfth century. They consisted of a circular bank and ditch enclosing a domestic area where a family and their livestock would have lived. Most were the farmsteads of ordinary freeholders rather than the seats of kings or warriors, though their sheer prevalence across the Irish landscape, estimated in the tens of thousands, speaks to how comprehensively they once organised rural life. The Gannaveen example has lost most of its bank to the plough and to time, leaving only the scarp, a change in ground level, to mark where the enclosure edge once stood. A second rath survives roughly 280 metres to the south-west, and the proximity of the two suggests this part of Galway once supported a reasonably settled farming community, with neighbouring enclosures perhaps occupied simultaneously or in succession across several generations.