Maengwyn Windmill is a circular rubblestone tower 9.8 metres high with an internal diameter of 6.5 metres, and walls 0.95 metres thick. Inside, cutouts denote the arrangement of heavy timbers which supported two working floors and the centreing ring for the cap. There are two doorways opposite each other on the ground floor, and rectangular window openings on the lst and 2nd floors. A slate plaque above the north-facing door recorded W H E (H E Williams) 1802. In 1975 a french millstone lay outside the tower.
W J Crompton, RCAHMW, 22 May 2008.