Two concentric ditches, or fosses, tracing an oval roughly fifty metres across, show up not as earthworks or visible remains but as cropmarks, the faint discolouration that buried features cause in growing crops when drought stress reveals what lies beneath the surface. A July 1989 aerial photograph caught them clearly enough: the inner fosse reading stronger, the outer one barely a suggestion.

Cropmark archaeology is a discipline that depends on luck and timing, on the right dry summer and a camera at the right altitude. What the 1989 photograph captured at Lisleagh was not just the buried ditches but also the trace of a field fence running east to west, bisecting the enclosure cleanly along its central axis. That fence appears on an Ordnance Survey six-inch map from 1937, meaning it had existed for decades before being levelled sometime between then and 1989, leaving its own faint impression in the soil. A macula, a dark soil stain suggesting possible disturbance or organic accumulation, was noted on the south side of that former fence line, slightly off-centre to the east. Whether the enclosure was a ringfort, a stock enclosure, or something earlier is not recorded; the double-fosse design, two concentric ditches rather than one, is less common than single-ditched enclosures and sometimes suggests greater antiquity or higher status, though without excavation that remains speculation.