This complex on the eastern bank of the Glashaboy river at Sallybrook, near Riverstown in County Cork, passed through at least three distinct industrial identities across roughly a century of mapped records, appearing on the 1842 Ordnance Survey six-inch map as a bleach and cloth mill, then as Pike Mill (Dyeing) by 1904, and finally as Glansillagh Mills, producing waterproof goods, by 1935. Fires in the late 1980s left much of it in poor condition, which is part of what makes what survives so legible as a record of layered industrial building.

The physical fabric of the complex reflects that long accumulation. The main range runs east to west across two storeys, with a wheel-pit on its western side measuring nearly five metres wide. A mid-nineteenth century wheel house covers the pit, its flat roof supported by a north wall that also serves as the outer wall of the structure to the west. A wide brick arch carries the head-race, the channel that brought water to drive the wheel, through the north elevation, while the tail-race, the outflow channel, exits southward through two tall round-headed arches before disappearing underground. The structure to the west of the wheel house is dated precisely by a keystone in its south wall bearing the year 1851. Two early nineteenth century sections nearby are finished with pedimented gables on their western faces, each featuring an oculus, a small circular window set into the gable, a detail that suggests a degree of architectural care unusual in purely functional mill buildings. A roofless two-storey structure hangs off the south-east corner, and a mill pond sits immediately to the north, feeding the head-race that runs south toward the wheel.