Ballyvennaght Mill, Mill Road, Near 144 Cushendall Road, Ballypatrick, Ballycastle, Co. Antrim

Ballyvennaght Mill is an 18th-century water-powered corn mill of exceptional rarity and completeness, dating from around 1780 to 1799. It stands on the right bank of the Carey River in a secluded rural setting surrounded by fields, accessed by a long unsurfaced track leading from the eastern end of a bridge on Mill Road, off the main Cushendall to Ballycastle road. The mill is currently derelict but retains outstanding industrial archaeological interest.

The building is two storeys, single bay, aligned north to south at the foot of a steep slope on the eastern edge of the Carey River flood plain. Its pitched natural slate roof survives, though there are no rainwater goods. The walls are of random rubble basalt and sandstone fieldstones — rounded stones gleaned from the surrounding land rather than quarried material, which itself is evidence of the mill's early date — with finely dressed projecting sandstone eaves. The north gable contains the only entrance, which has a wooden lintel with a sandstone relieving arch above it. Above the entrance, at first-floor level, is a large window opening, though both its head and frame are now missing. The east elevation is partly cut into the slope; at its southern end are the collapsed remnants of a small opening that originally lit the stone floor. The south elevation is otherwise blank apart from a small window opening at first-floor level on the left, and it is on this wall that the external waterwheel is mounted. The west elevation is blank except for a small slit window at each floor level at its right-hand end, with a blank recess of unknown function between and just to the left of these windows.

The waterwheel is mounted on the outside of the south gable. It measures 12 feet in diameter by 2 feet 3 inches wide and was backshot — that is, it rotated clockwise when viewed from outside the mill. With the exception of its cast-iron shaft and hubs and wrought-iron tie rods holding the sides together, the wheel is constructed entirely of wood: two sets of six arms, six pairs of rim segments held together with metal straps, 36 angled buckets mortised into the inside faces of the rim, and a soleplate. The woodwork is in poor condition and the buckets and soleplate are now missing. The wheel was fed by a long headrace that contours along the side of the valley from a weir across the river approximately a quarter of a mile to the south-east. The headrace remains largely intact, though the weir has gone. At the mill end of the headrace is a concrete emplacement, probably dating from the Second World War, with an overspill channel to one side. A timber launder would originally have carried water from the end of the headrace to the waterwheel; only the collapsed remains of an intermediate rubble masonry supporting pier survive. After passing through the wheel, the spent water flowed in an open channel north-westward back to the river.

Internally, the power transmission system and machinery are of exceptional completeness. The mill has single-step power transmission gearing connecting the waterwheel, shafts, and gears to a single pair of millstones, together with ancillary grain- and meal-processing equipment including a sack house. The waterwheel has evidently been rebuilt, probably more than once, and the machinery has also been replaced, possibly in the 20th century — both common occurrences in working mills. Nevertheless, this is one of the very few complete water-powered corn mills to survive in the Moyle District. Single-stone mills of this type are extremely rare in Northern Ireland: only two other examples are recorded, both in County Fermanagh. Wooden waterwheels are also exceptional. This type of arrangement was generally superseded during the 19th century by two- or three-stone mills driven by cast-iron waterwheels, making this an outstanding survival in a Northern Ireland context.

A short distance to the north-west of the mill stands a long two-storey ancillary building containing a dwelling house at its northern end and a grain-drying kiln at its southern end. The roof is of pitched natural slate but has collapsed at the kiln end. There is a red brick chimney on the north gable. Walls are of random rubble with roughly dressed sandstone quoins and remnants of limewash, and there are no rainwater goods. Openings are flat-headed with red brick heads. The house portion remains largely intact, though its interior has collapsed. The kiln has an external stone staircase to the first floor and a ground-floor doorway on its east side. The first-floor drying floor has collapsed, but a quarter-arched passage leading into the ground-floor fire hole survives. Beyond the house is a ruined single-storey, single-bay outbuilding, possibly a former pig sty, and there is also a small roofless lean-to at the east, at the bottom of the bank. To the north of the mill is a mid-19th-century road bridge, to the west of which stand the ruinous remains of a separate water-powered corn and flax mill.

The mill's vernacular character, scale, internal layout, use of fieldstone construction, long contouring headrace, and landscape setting are all entirely typical of small-scale 18th- and 19th-century rural water-powered corn mills and demonstrate clearly how river water was harnessed for motive power in the era before steam and electricity.

The historical record for this mill is well documented. It appears on the 1832 Ordnance Survey map and is recorded in the 1834 Valuation book as a "corn mill, kiln and dwelling" occupied by John Casement (and previously by Neal McGarry) at a rent of £16 per annum including two acres. The dimensions given at that time — 32 feet 6 inches by 20 feet in plan by 12 feet high for the mill, 24 feet by 18 feet 6 inches by 12 feet for the kiln, and 22 feet by 18 feet by 12 feet for the house — correspond with the present buildings. The quality letter assigned to the mill was '1C+', indicating that it was slated and old but in repair; the kiln was rated '1B' (slated, not new and slightly decayed); and the house '2C' (thatched, old and out of repair). The 1834 valuation records that the mill had a water supply for approximately eight months of the year but operated for only half the year. A 13-foot-diameter undershot waterwheel with 36 buckets powered one set of grinding stones. The valuation also notes that John Casement had "some little succon" — meaning that tenants in the vicinity were bound under the terms of their leases to bring their grain to this mill for grinding, paying the miller a fee, probably a proportion of the meal produced, for his services. The mill is explicitly captioned on the 1857 Ordnance Survey map. The 1859 Valuation book records John Casement as continuing to operate it, with dimensions given as 11 yards by 7 yards by two storeys for the mill and 8 yards by 6 yards by two storeys for the kiln — the same as in 1834 — and the same technical details as before. Thomas Boyd leased the house from Mr Casement and may well have served as the working miller. Valuation revision books record that Joseph Reed took over the mill in 1871, followed by Patrick McCormick in 1873 and Neill McCormick in 1911. The corn mill is captioned on the 1903–04 and 1922 Ordnance Survey maps. Neill McCormick's mill continues to appear in the valuations until 1955, after which it disappears from the record, presumably having ceased operations.