That combination, a documented route and a complete absence of certainty about its course, is precisely what makes it worth pausing over.

The sole record of this roadway comes from Francis Elrington Ball's 1906 history of County Dublin, where he notes, at page 219, that an ancient trackway once ran from Ballymount to the Belgard road, meeting it at the Shoulder of Mutton crossroads. Ball was a meticulous local historian, and the detail is specific enough to suggest he was drawing on older sources or local tradition rather than speculating. The crossroads name itself is the kind of vernacular landmark that tends to preserve memory long after the physical feature it described has been altered or forgotten; in Ireland, crossroads were frequently named after nearby inns or field signs, and the Shoulder of Mutton almost certainly belongs to that tradition. The roadway itself predates Ball's account by an unknown span of years, and its origins, whether medieval, early modern, or older still, have not been established. As the record compiled by Geraldine Stout notes plainly, the precise location of this roadway is unknown.

Ballymount today sits within the heavily developed industrial and retail corridor along the Naas Road, and the landscape Ball would have known has been substantially redrawn by motorways, distribution centres, and housing estates. A visitor interested in this trackway is therefore engaging less with a physical path and more with a question about what survives beneath tarmac and concrete. The Belgard road still exists, running through Tallaght, and anyone with an interest in early routes through south Dublin might find it worthwhile to consult the 1906 volume, available through libraries and digitised archives, to read Ball's original observation in context. The Shoulder of Mutton crossroads does not appear on modern maps under that name, which is itself a small piece of evidence about how quickly the older geography of even a recent city can dissolve.