The feature is a rath, the Irish term for a ringfort, which was the standard form of enclosed farmstead used across early medieval Ireland, typically dating from roughly the sixth to the twelfth century. Thousands survive across the country, but many have been levelled by farming or obscured by later development. This one endures, defined by a bank that rises just 0.65 metres from the forest floor, enclosing a roughly circular interior measuring approximately 24.5 metres north to south and 28.4 metres east to west.

The eastern side of the bank carries a gap about 2.5 metres wide, most likely the original entrance, orientated in the direction that many Irish ringforts traditionally faced. The interior is level, which is consistent with a site that once contained a dwelling or series of structures, though nothing visible remains above ground today. The plantation of conifers around and presumably over the monument means the earthwork now exists in a kind of muffled half-light, the trees both preserving and obscuring it. The place name Rathcobane itself contains the Irish word rath, suggesting the fort was significant enough to define the landscape long after it ceased to function as a settlement.