The enclosure, a D-shaped area roughly 30 metres east to west and 65 metres north to south, was removed during land reclamation, leaving only cartographic evidence and a brief researcher's note to account for what was there.

The two editions of the Ordnance Survey six-inch map tell slightly different stories. The 1838 edition shows a large, irregular area defined by field boundaries, suggesting something old enough to have shaped the surrounding landscape in a loose, organic way. By the 1929 edition, the feature had resolved into a cleaner D-shape, with its straight side running along the west and field boundaries radiating outward from it in several directions. That distinctive geometry matters, because a D-shaped enclosure with radiating boundaries is a recognisable signature of early ecclesiastical sites in Ireland, where a curved bank or wall would have delineated sacred ground attached to a church or monastic foundation. Lavelle, writing in 1994, flagged it as a possible ecclesiastical enclosure and noted the remains of a stone wall to the east of an associated church site nearby. The description also noted dense vegetation on high ground, which made the feature difficult to read even then. An aerial photograph confirmed the outline when ground conditions obscured it.

What makes the loss particularly quiet is the ordinariness of how it happened. Land reclamation has altered or erased countless such features across rural Ireland, places that survived centuries of neglect only to disappear under a different kind of pressure. The enclosure at Killour existed as a legible mark on the land in 1929, was still described, however tentatively, in 1994, and is now gone.