Bishop’s Mill, Abbacy Road, Ballywallon, Portaferry, Co Down, BT22 1PG

Bishop's Mill is a mid to later 19th-century water mill complex located on Abbacy Road, approximately three miles north of Portaferry in County Down. The principal structure is a small, two-storey random rubble-built mill with a gabled roof, set within a larger complex of sheds and stores of varying dates and states of repair, much altered in recent times.

The mill's north-east facing elevation fronts onto Abbacy Road and features a large double door opening to the right, with two small offset sash windows (one at ground level, one at first floor). The north-west gable contains the mill race with remains of the wheel mechanism; this elevation is otherwise blank except for the collapsed wheel. The south gable is largely obscured, being sandwiched between a larger modern-looking two-storey gabled store (joined to the mill by a recently constructed passageway) and another modern store to the south-west. An upper-level doorway on the south gable is reached via a long flight of stone steps. The mill is painted and has a pitched roof clad in Tullycavey slates with stone parapets.

Attached to the north-west elevation of the mill is a single-storey gabled building of similar age and construction, now partly roofed in corrugated iron, which runs parallel to the mill race. This building was originally a flax scutching mill. The mill retains much of its original machinery.

The corn mill originally dates from the 18th century. During the 1798 Rebellion it was burnt but was rebuilt shortly afterwards. The 1838 valuation records that the complex at that time consisted of single-storey buildings including a flax miller's house, flax mill, corn mill, and corn kiln. The corn mill was operated by pairs of stones and supplied with water for the greater part of the year. Both mills were then worked by John Allen. The small flax scutching mill, standing to the rear of the corn mill, operated until 1855, after which it became a store. The corn mill was rebuilt in 1896 after becoming derelict; the extent of this work is uncertain, though the fact that the mill is now two-storey (rather than single-storey as recorded in 1838) suggests major reconstruction occurred at some point after this date. The mill was noted as still in use in 1963 and again in the 1969 Ulster Architectural Heritage Survey, but work had ceased by spring 1970. The surrounding complex of buildings has been much altered in relatively recent times and now serves as storage.