Llyn Brianne Dam: Construction
The dam is a crushed and larger rock clay filled dam, all materials being obtained in the area itself. It is a man-made mountain blocking the valley.
The clay was taken from higher up the valley near Soar y mynydd chapel closer to Tregaron.
Much of the rock was quarried on site; this is now where you can park.
An on-site stone-crusher was used to reduce larger rocks to the various sizes required. A round-the-clock labouring system enabled its completion almost two years ahead of schedule.