A series of small, roughly rectangular fields once divided a gentle south-west-facing slope, their boundaries encoding centuries of agricultural life. Today, after ploughing and reseeding, nothing of that pattern survives at ground level. The only evidence that it ever existed is a single aerial photograph, catalogue reference Bruff Photo No. 5/2041, in which the ghost of the layout re-emerges as a faint trace readable from above.

Aerial photography has revealed many such vanished field systems across Ireland, particularly where repeated cultivation has levelled earthworks that might otherwise have persisted as banks or ditches. The Duncummin system was identified through this method and assigned the site reference Bruff Site No. 34. The fields appear to have been modest in scale and irregular in a way consistent with pre-modern agricultural practice, laid out according to the grain of the land rather than any imposed geometry. Roughly a hundred metres to the south, a separate enclosure, a defined area bounded by a bank or ditch, suggests that this was not an isolated feature but part of a broader organised use of the townland's ground.