A subrectangular enclosure, roughly 70 metres along its north-west to south-east axis and about 50 metres across, showed up as a cropmark on a GSI aerial photograph taken sometime between 1973 and 1977. Cropmarks occur when buried features, walls, ditches, or old boundaries, affect how plants grow above them, causing variations in colour or height that are invisible at ground level but legible from altitude. The result is a ghostly outline that the soil remembers even when the surface shows nothing at all.

What exactly this enclosure represents is not entirely clear. The most likely explanation connects it to an 18th or 19th-century field system rather than anything medieval or prehistoric. The northern edge of the enclosure, running north-west to south-east, aligns with a field boundary that was still present on the first edition Ordnance Survey six-inch map, surveyed between 1839 and 1840, but had already disappeared by the time that map was revised in 1945 and 1946. In other words, a boundary that had been part of the working landscape for at least a century was quietly erased within living memory of the aerial photograph that would later hint at its existence. The enclosure sits in the shadow of Bonnetstown Castle, which adds a layer of historical texture to the surrounding land, though the two features may have nothing directly to do with one another.