That much is recorded. Where exactly it stood, nobody now knows, which makes it a peculiar kind of monument: documented, real, and yet effectively vanished, leaving only a single line in a seventeenth-century survey to prove it ever existed.

The reference comes from the Civil Survey of 1654 to 1656, a detailed audit of land ownership and property carried out under Cromwellian administration across much of Ireland, published later by Robert C. Simington. The survey notes the presence of a dovecote beside Clontarf Castle, which at that period was the stronghold of the Vernons, an Anglo-Norman family with long-standing connections to the area. Dovecotes, sometimes called columbaria, were a mark of manorial status in medieval and early modern Ireland and Britain. They housed pigeons kept primarily for food, their eggs and meat providing a reliable protein source through winter months when fresh meat was otherwise scarce. The right to keep a dovecote was typically reserved for lords of the manor, which makes the Clontarf example entirely consistent with the castle's role as a seat of local power. That the survey bothered to note it at all suggests it was a substantial or otherwise notable structure at the time of recording.

Clontarf Castle itself survives, substantially rebuilt in the nineteenth century, and operates today as a hotel on Castle Avenue in Dublin 3. The grounds and immediate surroundings have changed considerably over the centuries, and no physical trace of the dovecote has been identified. There is no site to visit in any conventional sense, no earthwork or ruin to locate, and no marker to find. What remains is the documentary trace itself, held in the published Civil Survey volume, and the open question of where exactly the structure stood relative to the castle. For anyone with an interest in the material culture of the medieval and early modern Pale, that absence is itself worth sitting with.