That reason alone sets this site apart. Most ancient earthworks are lost to road-widening, ploughing, or simple neglect, but the fort at Corlust appears to have been cleared away as a matter of practical pest control, a fate that is, to say the least, unusual in the archaeological record of Ireland.

The knoll sits in a low-lying landscape tucked between drumlins, those rounded glacial hills that give so much of Monaghan its lumpy, enclosed character. The 1834 edition of the Ordnance Survey six-inch map shows a small rectangular enclosure on the rise, attached to an adjacent field to the north where a house also stood. By the time the 1907 edition was produced, the feature had been recorded differently, appearing as a roughly circular shape of around fifteen metres in diameter. That shift in shape between two map editions suggests either that the surveyors were interpreting a genuinely ambiguous earthwork, or that the site had already begun to change. A folklore account, collected through the Irish Schools' Manuscript Scheme, names it as a fort at Corlustia and preserves the detail about the rabbits. Whether the removal was a methodical levelling or a more gradual loosening of the ground over years of burrowing is not recorded. By 1995, the area had been extensively quarried, and no trace of any antiquity remained visible in what had by then become overgrown ground.