The raised area measures roughly 34 metres in diameter, and what gives it away as something older and more considered than a field boundary is the scarp, a steep earthen face running between 1.3 and 1.8 metres high, that traces its circumference with quiet insistence.

A rath is a ringfort, the most common type of early medieval settlement in Ireland, typically dating from somewhere between the sixth and tenth centuries. They were enclosed farmsteads, the bank and ditch marking out a household's space from the world beyond, and they survive in their thousands across the country, often absorbed into farmland and overlooked by anyone not specifically looking for them. At Rathmore, the enclosing features consist of a bank of earth and stone and an external fosse, which is simply a ditch dug to reinforce the bank's defensive or symbolic function. A report from 1976 recorded these details, noting that the original entrance could no longer be identified, the gap or causeway that would once have allowed people and animals in and out having been absorbed or obscured over the centuries. The place name itself, Rathmore, meaning "great rath" in Irish, suggests this particular enclosure may once have carried some local significance beyond the ordinary.