The large, imposing tower of Llancayo windmill is undoubtedly one of the largest, if not the largest, windmills to have been built in Wales, measuring 8.5m in diameter at ground level and standing to a height of 17m to the top of the stone tower.
The mill had a comparatively short life: it was erected shortly before May 1819 but, following an extensive fire, was out of commission, ruined and derelict, by 1830.
The five storey tower has recently been repaired and converted into accommodation; a new cap and sails are currently being installed. The first floor external gallery has been replaced and the large two-storeyed building, adjoining the mill tower to the north and which probably served as an oats drying kiln, has also been converted to accommodation.
B.A.Malaws, RCAHMW, 30 October 2008.