The site is a rath, the Irish term for a ringfort, a type of enclosed farmstead typically built between the early medieval period and around the twelfth century, in which a family and their livestock would have lived within a raised earthen bank and ditch. What makes this one quietly peculiar is how thoroughly the surrounding landscape has conspired to reshape it. Straight field fences have been built flush against all four sides of the enclosure, pressing in until the original round form has been effectively squared off, the geometry of modern agricultural Ireland imposed on something far older.

The rath sits on a ridge in Altbaun, Co. Mayo, positioned to make use of the natural break of slope to the north-north-west, with a stream or drain running along the townland boundary about 70 metres to the north-west. The site appeared clearly on the Ordnance Survey six-inch map of 1838, recorded as a circular embanked enclosure, but it does not feature on later map editions, suggesting it had already begun to fade from official notice as the landscape around it was reorganised. The remains today measure approximately 33 metres across in both directions. Low curved scarps, the remnant edges of the original bank, can still be traced along the northern, north-eastern, and eastern sides, reaching about half a metre in height, but at the south-west and north-west they have been absorbed entirely into the field boundaries and swallowed by thorn bushes. The interior is level and grassy, with a shallow oval hollow in the western quadrant, and there is an area of quarrying or disturbance along the southern edge.

What a visitor would see is less a monument than a palimpsest, the old circular logic of the place legible only in fragments, those surviving curves of earth at the north and east speaking across the field boundaries to what the whole enclosure once looked like, before the straight lines moved in.