The mill itself is long gone, its machinery dismantled and its purpose forgotten, but the outline of its existence has survived in old documents and older maps, suggesting that this corner of Donnybrook was once a site of practical, grinding industry rather than quiet contemplation.

The earliest record of a mill on the Donnybrook lands dates to 1524, noted by the Dublin historian F. E. Ball in his 1903 survey of the county's history. The mill's position is made clearer by a map attached to a lease from 1701, which shows it sitting immediately south of Donnybrook Castle, with a millrace, the artificial channel that directed water from a source to turn the mill wheel, running south-west towards the river Dodder. The Dodder, a fast-moving river that rises in the Dublin Mountains and cuts through the southern suburbs, would have provided exactly the kind of reliable flow that a working mill required. That combination of documentary record and cartographic detail allows the site to be located with reasonable confidence, even if nothing above ground announces it.

The probable location, according to researcher Danny Parkinson, falls within the present grounds of the Sisters of Charity, where a grotto now occupies the area. The site is not publicly accessible in any straightforward way, and there is nothing at ground level to mark it as a place of any particular antiquity. Those with an interest in the mill might instead approach it obliquely, by consulting Ball's original volume or examining the 1701 lease map, which together sketch the outline of a small industrial operation that once sat in the shadow of a castle beside a Dublin river. The grotto, quiet and devotional, offers no hint of the mechanical activity that preceded it by several centuries.