The only record of its existence comes from a single aerial photograph taken in July 1989, in which the buried remnants of a fosse, a defensive ditch, show up as a cropmark: a faint but legible difference in how vegetation grows over disturbed or compacted ground. The enclosure is roughly oval in shape and measures approximately forty metres in diameter, with what appears to be an entrance on the south-eastern side.

Cropmark archaeology depends on a simple principle. Where subsurface features such as ditches or walls interrupt the natural soil, crops growing above them respond differently, often appearing greener over a silted-up ditch, which retains moisture, or more parched where stone foundations lie close to the surface. These differences, invisible at ground level, can become legible from the air under the right lighting and at the right time of year, usually during dry summers when stress on crops is greatest. The 1989 photograph that captured the Boherascrub enclosure was taken as part of a systematic aerial survey of the Cork region, and it preserves what might otherwise have gone entirely unrecorded. The form and scale of the enclosure are consistent with the kind of enclosed farmsteads or ringforts that were common across Ireland during the early medieval period, though without excavation it is impossible to say more precisely what function this particular site served or when it was in use.