The feature only became apparent when satellite imagery was examined closely, and it raises the kind of question that makes archaeological survey quietly compelling: is this a structure someone built, or simply the ghost of a landscape doing what landscapes do?

The enclosure measures approximately 62 metres on its north-west to south-east axis and around 50 metres across the other way, making it a fairly substantial oval. It was identified as a cropmark, a phenomenon where buried or semi-buried features affect how vegetation grows above them, showing up as differences in colour or density when seen from the air. The band of the cropmark itself is roughly 4 metres wide. Simon Dowling spotted it on Google Earth imagery dated 18 April 2009. The setting, wet and marshy, complicates any confident reading of the feature, and the possibility has been raised that it may simply represent the edge of a natural pond rather than anything constructed by human hands. That ambiguity is part of what makes it interesting. Not every mark on the land resolves into a clear story.