The water-powered Esgair Moel Woollen Mill was built around 1760, and had interior modifications during the nineteenth century. In 1951 it was moved to the Museum of Welsh Life in St Fagans, Cardiff. It has whitewashed stone rubble walls and a stone tile roof. The internal waterwheel drives fully operational machinery.

B.A.Malaws, RCAHMW, 11 November 1998
Esgair Moel Woollen Mill was established c1760 on a site south-east of Llanwrtyd Wells (SN88894559). It was enlarged c1830 and later in the nineteenth century; it ceased work in 1947, was dismantled in 1949 for rebuilding at St Fagans, and reopened there in 1952, the second building to be completed at the Welsh Folk Museum.

The mill is a linear, two storey building of whitewashed rubblestone under a slate roof, the earliest part being at the south end, but with a late nineteenth century dyehouse on the south gable. Inside is the machinery to complete all the processes of woollen manufacture, including a carding engine, spinning and twisting machines, two handlooms on the upper floor, and a pair of fulling stocks, and power is provided by an internal waterwheel. All the processes are still actively demonstrated, and traditional shoulder shawls and blankets are produced, the latter being stretched after finishing on a tenterframe outside the building.

Information from Cadw Listed Buildings database and St fagans National History Museum website.
W J Crompton, RCAHMW, 9 January 2014.