On the northern slope of Balkill, somewhere within the dramatic headland of Howth, there is said to be a fort, an enclosure of some kind, that no one can now reliably locate. It exists primarily as a footnote, a name attached to a hillside, its physical form having slipped out of the record entirely.

The source for this elusive site is Thomas Johnson Westropp, the prolific antiquarian who spent decades documenting earthworks, enclosures, and fortifications across Ireland in the late nineteenth and early twentieth centuries. In a 1922 publication, he noted the presence of a fort on Balkill's northern slope, though even then the detail was spare. Enclosures of this type, sometimes referred to simply as ring forts or raths, were typically circular or oval earthen banks used as enclosed farmsteads during the early medieval period, roughly between the fifth and twelfth centuries. They are among the most common archaeological monument types in Ireland, yet even common things can vanish. Whether through agricultural clearance, coastal erosion, vegetation growth, or simply the passage of time, the feature Westropp recorded has not been confirmed on the ground since. Geraldine Stout, who compiled the record for this site in August 2011, noted plainly that the exact location of the monument is unknown.

Howth Head is well walked, with looped trails crossing its gorse-covered slopes and cliff edges throughout the year. The Balkill area sits on the northern side of the headland, away from the busier southern paths, and is accessible on foot though the terrain is uneven in places. Anyone with an interest in field archaeology might find it worth scanning the ground for any trace of an earthen bank or subtle change in topography, the kinds of low, grass-covered ridges that can sometimes suggest a buried or degraded enclosure. Spring and late autumn, when vegetation is lower, tend to offer the clearest views of the ground surface. There is no visitor infrastructure here, no signage, no marked point of interest, because the point of interest is, for now, officially missing.