On Derwen Hall Farmstead (nprn 408946) is a now roofless and ruined single storey stone building measuring 12m east to west by 4m; it stands some 15m to the north of the Hall (nprn 27107). Each pen has an iron feeding trough set in the wall with a vertical top-hinged iron flap over, allowing feed to be put into the trough from outside but accessed from within each pen.
B.A.Malaws, RCAHMW, 22 April 2009.