It does not appear as a mound or a wall or any feature you could stub your toe on; it shows up in aerial photographs taken in 2001 as a cropmark, the kind of faint discolouration in growing vegetation that betrays a buried fosse, a narrow ditch cut into the ground long ago and eventually silted over. Cropmarks form because buried ditches retain moisture differently from the surrounding undisturbed soil, causing the plants above them to grow at a slightly different rate, a difference invisible at ground level but legible from the air.

The site sits on a south-west-facing slope at Borrmount, and what the aerial photographs captured is a single narrow fosse defining that circular outline. Whether this represents an ancient enclosure of the kind commonly associated with early medieval settlement or agriculture, or something altogether more ordinary, is genuinely uncertain. The possibility has been raised that it may simply be a tree-ring, the circular stain left in the ground after a large tree, or a clump of trees arranged in a ring, has long since gone. Within a relatively short distance, two other features have been recorded: a ring-ditch roughly 130 metres to the south-south-west, and a second enclosure about 70 metres to the south-east. A ring-ditch typically refers to the remains of a prehistoric burial monument, its central mound eroded away and only the surrounding ditch surviving. Whether the proximity of these features to one another is meaningful or coincidental remains an open question.