The enclosure at Knockroe, in the Wilson townland of County Limerick, belongs to this category. It exists, officially, as a set of crop marks and soil shadows captured in a single frame of aerial film, its outline visible from the air in a way that gives no obvious indication of what might lie beneath the surface.

The monument was identified by The Discovery Programme, the state-funded archaeological research body, using medium-altitude aerial photographs taken in 1986. The record is catalogued under the reference LI023: Bruff 205: AP 4/3711, and was published as part of Martin Doody's 2008 volume, The Ballyhoura Hills Project, issued as Discovery Programme Monograph No. 7 by Wordwell. That project examined the archaeology of the Ballyhoura Hills region of south Limerick and north Cork, an area that had not previously received intensive survey attention and which yielded a considerable number of monuments known only through aerial reconnaissance. An enclosure, in this archaeological sense, refers to any defined area bounded by a ditch, bank, wall, or fence, encompassing everything from prehistoric farmsteads to ceremonial sites. Without excavation or further geophysical survey, the precise date and function of the Knockroe example remain unestablished.

Because the site was identified from aerial photography rather than ground survey, there is no visible surface feature that a visitor would easily recognise. The enclosure sits within agricultural land, and without specialist equipment or access to the original photographic record, its form is not apparent at ground level. Those with a serious interest in the monument can consult Doody's monograph directly, which provides the comparative regional context and the photographic references needed to understand what was recorded. The broader Ballyhoura Hills area rewards careful exploration for anyone interested in the quieter end of Irish archaeology, the sites that were never famous, never described by antiquarians, and only came to light when the technology existed to see them from above.