It measures roughly 26 metres in diameter, placing it at the smaller end of the ringfort spectrum, and it takes a practised eye to distinguish it from the surrounding farmland at first glance.

Ringforts, known in Irish as raths when earthen, were the most common form of rural settlement in early medieval Ireland, typically enclosing a homestead and its immediate working area within a bank and ditch. Most date from roughly the sixth to the twelfth centuries, though some are older. The Shanakill example belongs to this broad tradition, but carries a particular detail worth noting. P. J. Hartnett, writing in 1939, recorded the presence of a dry stone wall sitting on top of the original rampart. That wall has since weathered considerably, and what remains today is a low, eroded bank with stones scattered along portions of it, likely a mixture of original structural material and stones cleared from the surrounding fields over generations of farming. The relationship between those two phases, the earthen bank beneath and the stonework above, hints at a site that was reused or modified long after its original construction.