On a ridge in Carrownlabaun, County Mayo, a slight swelling in the pasture grass is very nearly all that remains of what was once a rath, the Irish term for a roughly circular earthen enclosure, typically dating from the early medieval period, that served as a farmstead and symbol of status for a family of some local standing. The rise is barely perceptible now, around sixteen metres across, and you might walk across it without registering anything at all.

Ordnance Survey maps from 1837 to 1838 recorded a roughly circular enclosure of around twenty-five metres in diameter, and the same feature appeared again on the 1922 edition, already beginning to lose its definition. By then, or sometime around then, field boundaries had been drawn across the southern and north-north-eastern edges, cutting into or absorbing the original shape. That process of incremental erasure, as agricultural land was divided and redivided over generations, is how most of Ireland's tens of thousands of ringforts have vanished. Here, the levelling is now effectively complete. Local memory, however, held on a little longer: people in the area continued to refer to the spot simply as "the fort", which suggests it retained some identity in the landscape even after its physical form had largely gone. The ridge itself still does what a rath builder would have wanted from a site, offering a broad view of the surrounding countryside and a clear line of sight towards a river lying roughly 270 metres to the south-east.