Tre'r-ddol Mills consisted of a windmill, Felin Newydd (NPRN24013) and a water mill working in combination. The water mill and its pond and leat are shown on the 1st and second editions of the 25-inch OS map, on the south-east and east respectively of the windmill, but by 1924 (3rd edition) the windmill was disused and the watermill building and pond had disappeared. Neither the mill nor the pond can be traced on the ground.
W J Crompton, RCAHMW, 25 June 2008.