Nothing breaks the surface; no earthwork, no ring of stones. What reveals it instead is the grass itself, growing in subtly different rhythms over buried ditches, producing patterns that only become legible from the air. This is a cropmark site, a category of archaeological feature where the buried remains of ancient ditches, known as fosses, cause the vegetation above them to grow differently depending on soil moisture and depth, creating outlines that satellite cameras can read even when the human eye cannot.

The enclosure was identified from satellite imagery captured on 14 July 2018, with the cropmark pattern subsequently confirmed by both Simon Dowling and Jean-Charles Caillère working from Google Earth Pro imagery dated 21 July 2021. What they traced was a large roughly circular enclosure approximately 74 metres in diameter, defined by a fosse of varying widths. The picture inside is more complex than a simple ring, however. Several curvilinear fosses within the outer boundary suggest internal divisions or features, and a deeper fosse running from the north-east around through the east to the south-east appears to indicate a smaller oval enclosure, roughly 50 to 56 metres across, that shares part of its western arc with the outer circuit. A small quarry, measuring approximately 40 metres by 30 metres, sits immediately to the south and clips the outer enclosure slightly, a reminder that agricultural and industrial activity has been quietly editing the landscape here for some time. The site sits on the eastern edge of marshland, a location that was often deliberate in earlier periods, when wetland boundaries offered both resources and a degree of natural protection.