The Cyfarthfa Leat is an old watercourse, running approximately 1000m from its source on the banks of the Taff Fechan to Cyfarthfa Lake and was originally built to also convey water to the ironworks.

The old Tramway running below the Leat on a shelf hewn from the rock face was built to transport limestone by horse drawn tram from the Gurnos Quarry to the Cyfarthfa Ironworks and it now forms a tree lined avenue which you can follow and from it view the Leat walls above.