The Old Mill at Bodnant was served by a mill race of Tudor origin and was used two centuries ago to carry water to provide power for blowing a blast-furnace on the banks of the River Conwy. The blast furnace has long ago disappeared; the power was subsequently used to turn the wheels of the corn mill and later to work the estate sawmills.

B.A.Malaws, RCAHMW, 09 June 2004.

The mill was built in simple Italianate classical style in 1837as an estate flour mill. It is a 5-bay, two-storeyed symmetrical building, with rubble walls with sandstone dressings and a shallow, hipped slate roof with deep eaves. The arched openings to the ground floor have projecting springing and keystones, and recessed dressed voussoirs beneath the arch-rings. The central entrance has a recessed, boarded and studded door reached via three slate steps, and leads to a central space which housed two water wheels, fed from a heavy iron launder above. There are 36-pane iron-framed square windows with blind tympana and projecting cills; and 30-pane iron-framed windows to the upper floor.

Source: DE/IND/SH77SE, from the Cadw Listed Buildings description.

A gasometer was marked on the 1900 to 1949 OS map. The gasometer indicates a private gasworks to light the house and estate.

J. Archer, RCAHMW, 1.12.2004.