The site betrays itself only as cropmarks, the faint but readable signatures left in vegetation when buried ditches or banks alter how soil drains and retains moisture, causing crops above them to grow at a slightly different rate or colour than the surrounding ground. It is that subtle difference, legible on satellite imagery, that reveals this enclosure at all.

The feature was identified and reported by Jean-Charles Caillère, who spotted it on Apple Maps satellite imagery. What the cropmarks show is a circular enclosure roughly 30 to 35 metres in internal diameter, with an overall spread of approximately 55 metres. It is defined by two concentric fosses, that is, ditches cut into the earth, one inside the other. The detail that makes the site quietly unusual is the relationship between them: the inner fosse is wider than the outer one, which inverts the arrangement more commonly assumed, where an outer boundary ditch would be the more substantial of the two. Whether that reflects the original function of the enclosure, a sequence of construction phases, or simply the accident of how two ditches have silted and settled differently over time, the cropmarks alone cannot say.