Maes y Cymmer Woollen Mill was built c1850 in the grounds of Maes-y-Cymmer House, itself built in 1826 by the Rev. John Jenkins of Hengoes, who until 1831 ran a printing press for religious texts at the site. Spinners and weavers are recorded in the area in 1851. Cloth was produced under several owners until 1920, after which some machinery is thought to have been removed. The building became a wool store.

The mill is a five-bay, three-storey and attic structure, built from rubblestone with dressings of yellow brick, and a slate roof. There is a narrow two-storey extension to the north which may be contemporary with the main structure, and a further two-storey extension which is not shown on the 2nd edition of the 25-inch historic O. S. maps. The earlier extension has a single-storey wing on its west side which, from the evidence of the O. S. map, covered the waterwheel. This was fed by a leat from a weir on the Afon Rhymney some 180 metres to the norht-east.

Information from Cadw Listed Buildings database.
W J Crompton, RCAHMW, 9 October 2014.