It does not announce itself with earthworks or standing stones. Most of the time, it is simply a field. But under the right conditions, the buried outline of something much older surfaces as a cropmark, the phenomenon whereby buried features affect how crops grow above them, producing subtle colour and height differences that become legible from the air.

The enclosure was recorded on the first edition Ordnance Survey six-inch map of 1839, where it appears as a roughly circular feature measuring approximately fifty-five metres on its north-west to south-east axis and fifty-one metres north-east to south-west, tightly hemmed in by existing field boundaries. By the time the OS revised its mapping around 1900, the enclosure had effectively disappeared from the record; the space is marked simply as a field. It was not until an aerial photograph taken in 1995 that the buried outline reappeared, rendered visible as a cropmark in tillage. Circular enclosures of this kind are a common but still not fully understood feature of the Irish landscape; many are the remains of ringforts, the enclosed farmsteads that were built and occupied predominantly between the early medieval period and around the twelfth century, though some enclosures have earlier or different origins entirely. What makes Ballycabus quietly awkward is that a field boundary, running roughly east-south-east to west-north-west, cuts straight through the centre of the enclosure, suggesting the earthwork had already been substantially reduced or levelled before the modern field system was laid out across it.