At Larkfield, the mill known as Mountdown occupies a site with a longer memory than its existing fabric might suggest, sitting atop ground that was already in use as a milling location during the medieval period.

According to Berry's 1891 account of the Dublin City watercourse, Mountdown Mill was built over, or came to occupy, the site of one of the many medieval mills that were established along this managed waterway. The Dublin City watercourse was a channel engineered to bring water from the Dodder into the city, serving both domestic needs and industrial ones, and the mills strung along it were essential to the economic life of the medieval town. Milling rights were valuable, contested, and carefully recorded, which is partly why traces of these sites survive in documentary sources long after the physical structures have been replaced or absorbed into later buildings. The Larkfield site is a quiet example of that layering, where a later mill was constructed on footings, or at least on a location, already shaped by centuries of earlier use.

The area around Larkfield sits in the south Dublin suburbs, and the watercourse landscape that once defined it is now largely invisible beneath roads, gardens, and development. Anyone interested in the site would do well to approach it with documentary sources in hand rather than expecting a dramatic ruin. The interest here is less visual than conceptual, the recognition that an ordinary-looking piece of ground can carry a medieval industrial history beneath it. Local and county heritage maps, along with the Historic Environment Viewer maintained by the National Monuments Service, can help identify the precise recorded location and any associated archaeological designations before a visit.