Drumlins, those smooth egg-shaped hills of glacial till that ripple across the Ulster landscape, were favoured spots for early enclosures precisely because their elevation offered both visibility and a degree of natural defence. The enclosure at Cordevlis would once have been legible as a raised earthwork, its bank describing a rough circle of around forty metres in diameter.

The 1834 Ordnance Survey six-inch map recorded it as an embanked enclosure with a house positioned just to the north-east, aligned roughly north-west to south-east. By 1967, the site had already contracted in appearance; a field survey described a raised, irregularly shaped area of around thirty metres across, the farmhouse beside it by then abandoned. A survey carried out in 1995 found the enclosure further reduced, surviving only as a curving stretch of field bank running from the south-east, around through the west, and up to the north-west. The diameter, still approximately thirty metres, matches the later estimates, suggesting what was lost was not so much the scale of the thing as its legibility as a coherent form.

What is quietly compelling about Cordevlis is the layering its brief history contains: an ancient enclosure, a farmstead built in its shadow and using it perhaps as a boundary, and then the farmstead itself falling silent, leaving the earthwork and the ruin to decline together at their own pace.