Small works built between 1838 and 1876. A semi-derelict building of red-brick which survived until the building of the new Plasmarl bypass road in the 1980s. Converted into the boiler-makers' buildings of Millbrook Ironworks (NPRN 301164) sometime between 1881 and 1897. Sited on the bank of the Trewyddfa Canal and almost certainly made use of its water.