At Ballygarraun in County Galway, on a gently south-facing slope among undulating mixed farmland, the ground shows nothing at all; no earthwork, no raised outline, no shadow in the grass. Yet the site is recorded, measured, and catalogued, a rectangular enclosure roughly 51 metres north to south and 32 metres east to west, now with no visible surface trace whatsoever.

The sole substantial description comes from Knox, writing in 1918, who noted even then that the enclosure was very poorly preserved. Rectangular enclosures of this kind are broadly associated with early medieval settlement in Ireland, sometimes serving as farmstead boundaries or enclosing a dwelling and its outbuildings, though without further investigation it is impossible to say anything more specific about the function or date of this particular example. By the time Knox recorded it, it was already fading. A century later, it has faded entirely into the field.