Gyfeillion Colliery was opened in 1851 and by 1866 was known as the Great Western Colliery, later Great Western Colliery and Coke Works. In addition to the original Gyfeillion shaft, the colliery included No.2 shaft, No.3 shaft and the Hetty shaft (nprn 275874), which were sunk in the mid 1870s, and a bank of coke ovens on the east side of the site. The winder house and headframe (nprn 33711), and fan house and drift (nprn 301542) at Hetty Pit are the sole surviving remains of the colliery.
B.A.Malaws, RCAHMW, 08 May 2008.