When the Ordnance Survey first mapped it in 1839, the enclosure measured around sixty metres across, a substantial ring defined by a bank and an external fosse, the fosse being a defensive ditch dug around the outside of the bank. By the time cartographers returned to revise the map in 1948, much of that definition had softened. The southern portion had effectively been absorbed into a field boundary, leaving only the northern bank and ditch clearly marked as a distinct prehistoric or early medieval feature.

What the ground no longer shows so plainly, the air has continued to reveal. On an aerial photograph taken on 9 July 1969, the fosse appears as a cropmark, a phenomenon where buried ditches and banks cause crops above them to grow differently, producing visible lines and shapes when seen from above. That same photograph shows a large dark area in the interior and spreading east and west across the fosse, a pattern that has been interpreted as possible evidence of former quarrying activity, suggesting the site was disturbed or exploited at some point after its original construction. Decades later, satellite imagery captured between 2005 and 2012 confirmed the enclosure is oval rather than strictly circular, measuring approximately fifty-six metres north to south and fifty metres east to west, with the fosse remaining traceable in the northern and south-eastern sectors.