That modest elevation is what survives of a ringfort, or rath, a type of enclosed farmstead built throughout Ireland primarily during the early medieval period, roughly between the fifth and twelfth centuries. Thousands of them remain scattered across the Irish countryside, but most have been softened by time into barely legible humps. This one at Leaffony retains enough definition to read clearly as a deliberate construction.

The bank forms a circle roughly 24 metres across, measured northwest to southeast. It varies in width and height around its circuit, running from about 2.6 metres wide at the north to 3.3 metres at the southeast, with the outer face notably steep, almost vertical in places. Embedded within that outer face are large stones, and this detail is telling. The incorporation of stonework into what would originally have been a purely earthen bank suggests that somebody, at some point in the relatively recent past, reinforced or altered the structure. The reasons for such modification are not recorded, but it is not unusual for old earthworks to be pressed into service as field boundaries or livestock enclosures long after their original function was forgotten. At the northern side, a narrow break of around half a metre interrupts the bank beside a section that is lower than the rest and similarly reinforced with stone. This may be the ghost of an original entrance, subsequently blocked up and only now legible as an anomaly in the bank's profile. The site sits approximately 140 metres southwest of the Leaffony River, close enough that the choice of this particular dry rise would have made practical sense to whoever first enclosed it.