A circular enclosure roughly 37 metres in diameter survives here, though survival is perhaps a generous word. Only a portion of the earthen bank that once defined it remains legible as a physical feature, running from the south through the west and around to the north. For the rest of its circuit, the monument announces itself only through a band of vegetation, the kind of subtle colour and growth difference that rewards a careful eye but is easily missed by anyone not looking for it.

Enclosures of this type are among the most common archaeological monuments in the Irish landscape. They are generally understood as the remains of a ringfort, a raised earthen boundary enclosing a homestead or farmstead, most commonly associated with the early medieval period, roughly the fifth to the twelfth centuries. The earthen bank, or sometimes a combination of bank and ditch, would have defined a domestic space, offering both a degree of physical protection and a clear marker of a household's territory and status. Thousands survive across Ireland in varying states of preservation, though many have been lost entirely to ploughing, development, or the slow work of time. The Castlegar example sits within what was later shaped into a demesne landscape, the kind of designed estate grounds that became common around country houses in the eighteenth and nineteenth centuries, and it is now farmland, the older feature quietly persisting beneath the more recent land use.