That particular sequence of priorities, livestock and hounds displacing a place of public execution, tells you something about how the landscape around the city's western approaches was being quietly reorganised in the later seventeenth century.

The detail comes from F. Elrington Ball's 1906 history, which noted that near the Dublin entrance to the estate there had been a dairy and a dog-house, the latter tended by a man named Plumer, who looked after a large kennel during the time of the Duke of Ormonde. Ball suggested it was probably the construction of these functional estate buildings that prompted the relocation of the gallows to a more retired position near Kilmainham. The Duke of Ormonde, one of the most powerful figures in seventeenth-century Irish administration, maintained considerable holdings in and around Dublin, and the reorganisation of such a property would have been entirely in keeping with the period's broader reshaping of the city's hinterland. Plumer himself is otherwise unknown, a single name preserved almost by accident in a passing observation about kennel management and judicial infrastructure.

The difficulty for anyone curious enough to investigate further is that the exact location of this structure is now unknown. No coordinates survive, no mapping record pins it down, and the landscape around Castleknock has changed substantially since Ball was writing. What remains is the record itself, a fragment of social and administrative history in which a gallows and a kennel briefly occupied the same sentence, and in which the needs of a ducal household appear to have outweighed the convenience of public execution. The site, wherever it stood, is as much an absence as a place.