This isolated, sinuous spoil tip on the south-west side of Cwmorthin is probably an early tip from the workings at Level 1, the Lake Level. It was formed from one line of tramway, extended as the tip grew, and it has no sideways development. (NB, the spoil tips higher up on the south-west valley side are from Wrysgan Slate Quarry, NPRN 40602.)
W J Crompton, RCAHMW, 4 December 2008.