There is no earthwork to speak of, no raised bank or hollow, nothing that would catch the eye from ground level. The only way to see it is from above, and even then only under the right conditions: it appears as a cropmark, a faint geometric outline pressed into the growing crops by whatever buried structure lies beneath.

Cropmarks form when buried features, such as walls, ditches, or filled pits, affect how plants grow above them. Soil over a buried ditch retains more moisture, producing lusher, taller growth; soil compressed by an old wall drains more quickly, leaving stunted, paler crops. From the air or in satellite imagery, these differences in growth register as lines and shapes. In this case, the shape is a sub-square enclosure measuring roughly 18 metres east to west and 16 metres north to south, identified by Jean-Charles Caillère from Google Earth imagery dated 14 July 2018. Just four metres to its west sits a second, somewhat smaller enclosure of a similar form. The two together suggest a paired arrangement, though what purpose they served, and when they were constructed, remains unknown from what survives at the surface.