The six-inch Ordnance Survey map produced between 1899 and 1902 marked the site as a 'Nunnery (in Ruins)', a designation that turns out to have been entirely wrong. What actually survives at Loughill is the remnant of a mill, sitting in a patch of wet, marshy ground where a side channel of a stream separates itself from the main watercourse flowing north towards the Owenbeg River. The land between the two streams forms a small island, and it is on the eastern bank of the quieter channel that the building's last standing stones can be found.

The walls that remain are built from roughly coursed limestone and shale rubble, bonded with a lime mortar mixed with pebbles, a fairly typical construction method for rural mill buildings across Ireland. The upstanding section of the west wall runs only about 2.2 metres in length and is between 0.6 and 0.7 metres thick, with a short return of 0.7 metres at the north-west angle, where flat stones serve as quoins, the corner-stones that give a wall its structural edge. From there, a collapsed run of the same west wall can be traced southward for a further six and a half metres or so, suggesting the original building was considerably longer than what now stands. The mill race, the channel cut to direct water onto the mill wheel, is still legible in the landscape: four metres wide, shallow on the eastern side and dropping to a steep bank on the west, which would have helped concentrate the flow and give the wheel its working force.