It exists, officially, because an aircraft passed overhead in 1973 and a camera recorded something that the ground refuses to show.

An enclosure, in Irish archaeological terms, is typically a defined area set apart from its surroundings by a bank, ditch, or wall, and such features were used across many centuries for purposes ranging from settlement and agriculture to ritual. The one at Cloghleagh was identified purely from aerial photographs taken by the Geological Survey of Ireland in 1973, and that photographic evidence was enough to earn it a formal listing in 1986 and again in 1995. Aerial photography can reveal buried or low-lying earthworks through crop marks or soil discolouration that are simply invisible at ground level, which is precisely the situation here. The forestry plantation that now covers the site has made even that indirect kind of visibility impossible; the trees have closed off both the view from above and any meaningful reading of the ground below.

This is, in a practical sense, a site that exists more fully in a filing cabinet than in any landscape a person could walk through. The enclosure at Cloghleagh is not accessible, not visible, and not interpretable without the archived photograph that first brought it to attention. It is, in its quiet way, a reminder that a significant portion of Ireland's archaeological record is held together by evidence this fragile, a single overflight on an otherwise unremarkable day fifty years ago.