Melin Esgob was a large 2-storey stone complex of buildings, in process of conversion to a dwelling in 1975. The main building, 10 by 6.6 metres and built against the valley side so that its main entrance was at first floor level, had a two-storey extension to the north, with a further extension in ruins. The frame of an impressive composite overshot wheel, 5.5m diameter by 1.37m wide on a square iron axle, was in situ on the north-west gable of the main mill, but the overhead launder had been removed. Inside, the 2.23m diameter cast pitwheel, cast wallower and vertical wooden shaft were in situ, the latter reaching up to the ceiling of the first floor to a large cast iron spur gear and horizontal drive pinion. This showed that the stones were overdriven, but they had been removed and their layout lost in the renewal of the floor timbers. The mill leat came from a small stream, not from the nearby Afon Goch.
The conversion made little progress until 2003, when a new owner took on the task. The whole building and its ruined extension have been repaired, with the cast centres of stone nuts built into the gables. The wheel has been restored, set at a higher level to raise it above the tail race. Inside, the main shaft, pitwheel and wallower, and great spur wheel have been retained and form striking features in a conversion of high standard.

Melin Esgob, Bishop's Mill, was leased to the Bishop of Bangor in 1425 (R. O. Roberts, The Mills of Anglesey, Transactions of the Anglesey Antiquarian and Field Society, 1958, pp 1-15). Later it was owned by the Bulkeley family; a lease of 13 November 1817 required the lessee to erect, rebuild and finish a new mill 30 feet long and 18 feet within the walls, at a cost of at least £200 above the sum of £100 granted by Bulkeley. It is labelled 'Corn mill' on all three editions of the 25-inch O.S. maps.

W J Crompton, RCAHMW, 19 November 2008.