What revealed it was a single aerial photograph taken on 16 July 1971, in which the soil and crops above buried features had dried out unevenly, leaving ghostly linear marks across the frame. These cropmarks, three or four parallel lines running roughly east to west, are the kind of evidence that can vanish entirely in a wet summer and appear with startling clarity in a dry one.

Cropmarks form when buried ditches, walls, or disturbances affect how plants above them grow and ripen. Ditches that were backfilled tend to retain more moisture, producing lusher, darker growth; compacted surfaces or buried stonework do the opposite. In the 1971 photograph, the southernmost of the parallel marks are noticeably fainter, suggesting whatever lies beneath them is less well preserved or sits at a greater depth. The field system does not stand alone in this landscape. Two ring-ditches, the circular buried remains of what were likely prehistoric burial monuments or enclosures, sit in close proximity: one approximately ten to fifteen metres to the south-south-east, and another nearby. The possibility that the linear field boundaries and the ring-ditches are connected, perhaps part of the same organised agricultural or ceremonial landscape, has been noted, though the evidence does not yet settle the question.