Porth Neigwl lead mine (nprn 33792) at Tan yr Allt, Llanengan, was one of several in the area and may date from the seventeenth century or earlier. On the hillside to the south east stands a tall circular chimney, built of rubble stone to about mid-height and above in red brick banded with yellow brick. The chimney is believed to have been built about 1878 and although there is evidence of covered flues in the field below, converging on the chimney, whether it was used for mine ventilation, as a flue for an engine or for a smelter is not clear.
There is an image of this site under nprn 33792.
B.A.Malaws, RCAHMW, 17 July 2009.