The structure sits on a narrow terrace above a stream that reaches the River Moy estuary just ten metres to the east, and the builders made the landscape do much of the structural work for them: the natural scarp forms the southern wall, while the northern wall, rising to around five metres, doubles as a facing for the vertical drop at the terrace's edge. The eastern wall similarly aligns with a sheer fall. It is an unusually economical piece of construction, the stonework filling only the gaps that geology left open.

The mill appears on the Down Survey Barony map of 1656 to 1658, which places it firmly in the seventeenth century at the latest, though the building may be older. The Down Survey, carried out under William Petty to document confiscated Irish land, is one of the earliest systematic cartographic records of the country, so its appearance there is reasonable evidence of the mill's significance at the time. The building itself is rectangular, measuring roughly 8.45 metres east to west and 6 metres north to south, with coursed, mortared stone walls 0.6 metres thick. The western doorway, two metres wide and two metres high, is finished with a shallow arch of voussoirs, the wedge-shaped stones that distribute weight across an opening, and retains a drawbar socket in the southern jamb, just at the point where the arch begins to spring. A matching socket in the northern jamb is partly destroyed. One blocked-up opening near the north end of the eastern wall is a curiosity: it sits just above interior floor level but would, on the outside, have opened directly onto a vertical drop. A stone-built sluice twenty metres to the west channels a narrow stream towards bedrock cascades beside the mill, preserving part of the water-management system that once drove it. The later Ordnance Survey maps of 1838 and 1929 show a building on this spot but do not identify it as a mill, suggesting its original function had been forgotten or had long since ceased.

The mill does not stand alone. A castle occupies elevated ground on the northern side of the stream, a church and graveyard lie roughly fifty metres to the south, and a rath, an early medieval circular enclosure, sits about two hundred metres to the southeast. The cluster suggests that this stretch of the Moy estuary was, for a considerable period, a place of some local consequence.