In 1969, reconnaissance flights over low-lying pastureland near Ross Errilly friary in County Galway captured something that centuries of ordinary farming had not quite erased: a coherent pattern of roughly rectangular fields, defined by earthen banks, stretching some 280 metres northeast to southwest and 130 metres northwest to southeast. Cultivation ridges, the corrugated signatures of medieval or post-medieval tillage, were clearly visible within them. By the time another set of aerial surveys was carried out in 1986, parts of the field system had already been lost, a substantial bank and fosse, that is, an earthen embankment paired with a defensive or drainage ditch, still obvious along the eastern and southern limits in 1969, had been partially removed in the intervening years.

The question of what exactly these boundaries represent has not been fully resolved. Writing in 1901, a scholar named Cochrane described an enclosing wall and ditch belonging to the monastery at Ross Errilly, and it is plausible that what the aerial photographs captured is some remnant of that monastic precinct. Ross Errilly itself is one of the better-preserved Franciscan friaries in Ireland, and like most such institutions it would have maintained agricultural land to sustain its community. Yet the geometry does not quite fit: the field system's boundary runs noticeably inside the position of the friary's gatehouse, which complicates any straightforward identification of the earthworks as the outer monastic enclosure. The relationship between the fields, the banks, and the friary's own boundaries remains an open question, one that the slow attrition of earthmoving may eventually make impossible to answer.