Garnddyrys Ironworks (nprn 34137) was a forge in operation c1817-61. The spoil heap is probably related to the demolition of the works and its associated houses, as it is in an unlikely position for dumping forge waste. It is formed of undulating ground approximately 10m square and up to 10m high, although the natural ground level rises steeply here.
R Hayman, Hayman & Horton, 26/11/2003