Princes Yard Factory is a former woollen mill built c1840 on the site of a much earlier mill, possibly dating from the seventeenth century. It was famous for the manufacture of gloves, and was in operation until c1900, when it became a cheese factory until 1932. It was then bought by the Youth Hostels Association, becoming one of the earliest of Britain's youth hostels.

The building has two storeys and four bays, and is constructed of large random stone blocks under a pitched slate roof. It retains some of its 16-pane windows. Inside, the first floor is supported on plain cross beams and cast iron columns, and line-shafting remains in situ on the ground and first floors. The waterwheel was housed in a wheelhouse at the south-west gable which once had a lean-to roof. The leat was shared with Felin Uchaf upstream and Felin Isaf some 160 metres downstream; the wheel is thought to have been moved to Felin Isaf.

Source: Cadw list description, 2004. 2004.02.17/RCAHMW/SLE