That ambiguity is, in its own way, the most interesting thing about it.

The feature first appeared on the Ordnance Survey six-inch map of 1842, drawn as a roughly rectangular depression measuring approximately 40 metres by 30 metres. By the time the same area was mapped again in 1906, and again in 1937, the cartographers rendered it differently: as a hachured sub-circular enclosure, the short parallel lines used on OS maps to suggest raised or banked edges. The shape had apparently changed, or at least the interpretation of it had. When it was catalogued in 1988, it was classified as a levelled enclosure, the kind of designation that suggests a ringfort or similar earthwork reduced by time and agriculture. A decade later, a revised record reclassified it simply as a quarry. The current thinking is cautious: it may be a natural hollow, or it may be a quarry that was later enclosed by a protective bank at some point after 1842. The evidence does not comfortably support treating it as an archaeological monument at all, and that verdict, provisional and honest, has simply been left to stand.