Main Mill Building at Museum of the Welsh Woollen Industry.

Woollen mill building of the earlier C20, comprising 2 parallel blocks, aligned roughly NW-SE. S block is L-plan. The space between the blocks is currently roofed over. 2 storey and loft in rubble stone with slated, pitched roofs and cast iron rainwater goods. Large windows, generally with red brick dressings and arched heads - mainly 16-pane windows with swivelling upper lights. Elevation to yard has 16 bays. 1st floor, 9th bay has boarded timber loading door with gabled attic, further similar loading door above. Ground floor, 2nd, 5th, and 11th bays are doorways. Beneath 15th window is cast iron overshot waterwheel. L (W) gable end has later lean-to in brick and attic loading door. To L, 2-storey block with monopitched upper storey, in angle with parallel N range, also in brick. To L of this, parallel N block has doors to L, windows on each floor to R. Gable end has 3 windows at 1st floor level, 2 smaller loft windows, and 2 windows to ground floor outer bays. Rear elevation of 12 bays, with similar glazing to S front. E gable has 12-pane window to attic and loading doors to each floor, set to L. SE return of S block has, to 1st floor, 7 square 12-pane windows, apparently reduced in depth, with red brick dressings. Ground floor has similar 12-pane windows with yellow brick dressings. Slate sills throughout. Blocked former window located 4th bay from L.

The buildings retain early C20 roof structures to lofts, and wooden floors and beams, strengthened in places with iron stanchions. Ground floor has quarry tiles. Power shafts remain in situ. The machinery is a mixture of units from the working mill, (but said to have been imported in 1950s), including mule with 400 spindles to 1st floor rear block, and museum exhibits intended to illustrate the history of the woollen industry.