[2] Its source is a number of streams that include the Afon Diliw, located on the west slopes of Plynlimon on the border of Ceredigion and Powys in the Cambrian Mountains.

[3] The Ystwyth flows westwards before its confluence with the Afon Rheidol and the estuary at Aberystwyth to drain into Cardigan Bay.

It is reputed that the average age at death of the miners in Cwm Ystwyth was 32, largely because of acute lead poisoning.

The result was a landscape that became famous and attracted many visitors, including Samuel Taylor Coleridge, and it is believed to have inspired a passage in his poem Kubla Khan.

Water is drawn away from the mine in a leat to a wetland area, where biological processes involving the vegetation immobilise much of the pollutants.