The circular earthwork at Barleyhill is a rath, a type of ringfort that would once have served as an enclosed farmstead, its banks and ditches marking out a defended living space for a family of some local standing. What makes this one quietly interesting is its bivallate form, meaning it carries two concentric lines of defence rather than the single bank more commonly encountered across the Irish countryside.

The inner bank describes a roughly circular area just under 37 metres across and, though time has softened its profile, it still rises to an external height of around 3.3 metres on its southern side. A broad internal slump along the bank gives the interior a gently dished appearance, as though the ground has settled inward over many centuries. Beyond the inner bank lies a fosse, a defensive ditch, most legible now as a shallow depression on the western and north-eastern sides, and beyond that the traces of a second, outer bank that has been largely levelled. On the eastern and south-eastern edge, even those faint traces have been cut through by an avenue running northward to Barleyhill House, a reminder that later landowners reshaped the landscape around such monuments without necessarily registering what they were disturbing. A gap of roughly two metres in the inner bank on the eastern side may mark the original entrance, though the slumping of the earthwork makes it impossible to be certain.