The 1st edition of the 25-inch O. S. map depicts Felin Pant-haulwen as a corn mill on the west bank of the Afon Cerdin, and supplied by a leat 370 metres long. By the time of the 2nd edition map (1900?) the much extended buildings had become woollen mills, under the name Pantolwen Mills. The Listing applies only to the former corn mill. It has three storeys, built into a bank, and is built of rubblestone with a hipped slate roof.

Information from Cadw Listed Buildings database.
W J Crompton, RCAHMW, 6 November 2014.