Yet the shape of it, that broad, deliberate curve, is the only thing left to mark where a castle once stood.

The sole written clue comes from the Reverend William Carrigan, whose four-volume history of the Diocese of Ossory, published in 1905, recorded that Dreeling's castle stood in what was then James Hogan's land in Brittas, and that by Carrigan's time the structure itself had already vanished entirely, leaving only the large earthen rampart that had enclosed it. A rampart of this kind would have formed the outer defensive boundary of a castle complex, a bawn-like enclosure meant to protect the buildings and livestock within. Carrigan remains the only source connecting this particular earthwork to a castle, and no other record has surfaced to corroborate or expand on what he wrote. The name Dreeling is otherwise unaccounted for in the surviving record.

What survives, then, is essentially a ghost of a perimeter: the enclosing wall of a place whose interior has left no visible trace. The overgrowth that now fills it has, in a way, preserved the earthwork from disturbance while simultaneously making it difficult to read. It is the kind of site that rewards patience and a good map, and an awareness that the densest patch of scrub in a field is sometimes the most historically significant thing in it.