Not a castle or a church or a monument of any obvious civic importance, just a dwelling, one of two shown in this area on a mid-seventeenth-century survey map. That it appears at all is the reason it remains of interest.

The Down Survey of 1655 to 1656 was an extraordinary undertaking commissioned by the Cromwellian administration to map the forfeited lands of Ireland following the wars of the 1640s. Carried out under the direction of William Petty, it produced some of the earliest detailed cartographic records of Irish townlands, and the maps it generated are now among the most important sources we have for understanding the rural landscape of that period. The house at Castlefarm appears as one of two dwellings marked in the area, recorded alongside a companion structure catalogued separately. Beyond that, the record is thin. The site has not been precisely located, and no further details about its construction, its occupants, or its fate have been established. Geraldine Stout, who compiled the entry in 2011, noted only what the map shows.

Because the site has not been pinpointed, there is no specific location to visit in the conventional sense. The townland of Castlefarm lies in County Dublin, and anyone with an interest in the Down Survey maps can access digitised versions through the Trinity College Dublin library and related online archives, where the original survey sheets can be examined directly. What the map offers, even without a physical site to stand on, is a glimpse of a landscape that was being systematically recorded at a moment of profound disruption, when ownership of land across Ireland was being assessed, reallocated, and written down for the first time in this kind of detail. Two small houses in a Dublin townland, drawn in ink, surviving when the buildings themselves did not.