A single section of the south wall survives, standing just 1.3 metres high and stretching five metres in length, its lower courses preserved on the flat floodplains of an otherwise upland stretch of countryside. Alongside it, faint traces of a mill pond and a millrace, the channel cut to carry water from the river to power the mill wheel, can still be made out in the field immediately south of the wall. A possible retaining wall for the pond or race survives in the same field. The river itself appears to have been deliberately diverted at some point upstream, fed down along the silted millrace, and then returned to its natural course at the bridge over the Multeen to the south.

The site has a long history buried beneath its current near-invisibility. A water mill at Rossacrow was recorded in the Civil Survey of 1654 to 1656, a comprehensive Cromwellian-era land survey compiled to assess forfeited Irish estates, which places milling activity here well over three and a half centuries ago. By the time of the first edition Ordnance Survey six-inch map in 1840, the structure was recorded specifically as a corn mill. The 1903 edition of the same map shows the footprint of the building that left the surviving wall. Writing in 1917, a commentator named Seymour described the site as consisting of the foundations of a more recent mill, with a considerable length of the old millrace still traceable back along the slope of Rossacrow and parallel to the river. That layering of one mill upon the remains of an earlier one hints at a site that was repeatedly rebuilt and reused as the agricultural economy of the area demanded.