Cropmarks form when buried features affect how plants above them grow, with ditches retaining more moisture and producing lusher, taller crops that show up as darker lines from the air. What the photograph revealed was a structure roughly 120 metres across on its east-west axis, defined by two concentric fosses, or ditches, enclosing a substantial area of ground.

The southern portion of the enclosure, lying south of a roughly east-west field boundary, was the more legible part of the cropmark, running to around 40 metres north to south. The outer fosse could also be traced for approximately 20 metres north of that same field boundary on the eastern side. The site sits within what is now the Bennettsbridge limestone quarry, and by the time satellite imagery was examined in April 2021, the picture had changed considerably. Industrial extraction had disturbed much of the area, and a quarry road running northwest to southeast cuts directly through the enclosure. What the 1969 photograph preserved as a coherent, if tentative, archaeological outline had been, at least partially, quarried away in the intervening decades. The site remains unclassified in terms of period or function; its rectangular form and concentric ditches suggest a deliberate enclosure of some significance, but without excavation, the questions it raises stay open.