Part of the plateway system connecting various ironstone and coal levels on the western slopes of the Taff valley with Cyfarthfa Ironworks.
(SO03780646-SO03610637).

1884 (OS 6-inch 1st Edn.): A branch running from the Cwm-glo Pit-Cyfarthfa Ironworks line into Pen-y-heol-gerig Quarry.

1905 (OS 6-inch 2nd Edn.): Still extant