Felin Isaf has two water mills built to grind clover, wheat and other grains. The first recorded mention of Felin Isaf was in 1699, although it is believed that the oldest building, the clover mill (nprn 24863), dates from 1680. The main corn mill (nprn 85443) was built in 1740 and there is also an oat drying house (nprn 85445) that was built in 1855. To the south is the millhouse (nprn 27153).
The mills operated until 1942. Restoration began in 1978. Both mills contain machinery that includes cogged wheels and pulleys, belt-operated sack hoists, octagonal grain hoppers and feed and flour shutes, sieves and flour troughs. Most of the machinery is original although some pieces came from a local windmill. The site is occasionally open to the public.

Sources:
Welsh Mills Society published leaflet, 1999;
Site visits by B.A.Malaws, RCAHMW, 27 April 1996 & 25 April 2015;
RCAHMW site file DE/IND/SH87SW;
Cadw Listed buildings database;
David Gwyn & Merfyn Williams (1996) `A Guide to the Industrial Archaeology of North West Wales?. Association for Industrial Archaeology.

RCAHMW, 21 May 2015.