It was recorded that way in 1992, and again in 1996, based largely on its appearance on a 1916 Ordnance Survey six-inch map, where it showed up as a modest hachured area, those short radiating lines cartographers use to suggest raised or sunken ground. It took an on-the-ground inspection in 2002 to establish what the feature actually was.

When someone finally looked closely, the site turned out to be a quarry, roughly 14.5 metres north to south and 11.7 metres east to west at its base, cut to a depth of around 1.2 metres. A bank, about 2.8 metres wide, runs along the southern side only. This bank is not a defensive or boundary feature but simply the upcast, the material thrown up when a trench was dug running from the south-east to the south-west of the interior. It is a mundane explanation, in a sense, but also a quietly instructive one. The site illustrates how easily a feature can be misread at a distance or from a map alone, the hachuring that once suggested something ancient and enclosed turning out to mark nothing more than extraction and spoil.