What looks at first like an unremarkable rise in the landscape resolves, on closer inspection, into a curving arc of earthen bank, roughly three metres wide and running about thirty-four metres from south-west to north-east, accompanied by a line of hedge. The bank stands only around thirty centimetres above the interior ground level, but rises to about one and a half metres on its outer face, a difference that hints at the original purpose of such an enclosure, even if time and agriculture have softened it considerably.

A ringfort, or rath, is a circular or roughly circular enclosure defined by one or more earthen banks and ditches, typically dating from the early medieval period in Ireland, roughly the sixth to the twelfth century. They served as enclosed farmsteads, the defended homesteads of farming families, and they are among the most numerous surviving field monuments in the Irish countryside. The Garryhack example retains its local name, a rath, though no fosse, which is the external ditch that typically accompanied the bank, is now visible at the surface, nor is any original entrance apparent. Whether these features were once present and have since been lost to erosion and agricultural activity, or whether the enclosure was always somewhat simpler in construction, is not clear from what survives.