The first edition Ordnance Survey six-inch map, surveyed in Ireland during the 1830s, marks a windmill at this location, a single symbol that raises more questions than it answers about what once occupied this patch of south Dublin.

The first edition OS maps were produced as part of a vast and methodical survey of the entire island, undertaken by the Ordnance Survey of Ireland from 1824 onwards and representing one of the most detailed mapping exercises carried out anywhere in the world at that time. The surveyors recorded not just roads and field boundaries but structures of every kind, including mills, which were working features of the landscape rather than curiosities. Windmills were never especially common in Ireland compared to watermills; the country's abundant rivers and streams made water power the more practical choice in most places. Where windmills did appear, they tended to serve specific local needs, often grinding grain in areas where a reliable watercourse was not available. That one existed at Rathfarnham, on the southern edge of Dublin, suggests some level of agricultural or commercial activity in the area during the period before the map was made, though the precise date of construction and the name of whoever built or operated it are not recorded in the surviving evidence.

Because nothing of the structure appears to survive above ground, or at least nothing that has been documented, a visit to this spot is more an exercise in reading the landscape than in examining a physical remain. The OS six-inch maps themselves are freely available through the Irish historic maps viewer maintained by Tailte Éireann, and comparing that first edition sheet against a modern map is often the most revealing way to orient yourself. Looking at the terrain around Rathfarnham with the map in hand, it is worth considering what the local topography would have offered a miller in terms of prevailing winds and open exposure, the practical calculations that determined where such a structure could function. The absence of the building is itself part of the record.