Where archaeologists might expect a ring-fort or some other earthwork, the ground offers nothing: no bank, no ditch, no visible trace of ancient boundary-making.

The earliest Ordnance Survey six-inch maps show the site not as an antiquity but as an oval grove of trees, sitting at the north-eastern tip of a glacial ridge that runs roughly north-east to south-west across otherwise flat, wet grassland. Glacial ridges of this kind, formed from material deposited by retreating ice sheets, often provided the only firm, dry footing in low-lying boggy terrain, and this one appears to have been put to practical use. To the south-east of the grove lay an osier bed, a managed plantation of willows grown specifically for their flexible rods, which were harvested for basket-making and similar crafts. The grove of trees on the ridge may have supplied timber for that same industry, or it may simply have been a deliberate landscape feature planted on the one patch of ground dry enough to sustain it. By the time the later Ordnance Survey editions were produced, even the trees were gone, leaving only the oval outline on the older maps to prompt the question of what had stood there.