Cerrig llwydion uchaf is the upper lake, it has gin clear water and a few small wild brown trout.

Cerrig llwydion isaf is the lower lake, it is quite boggy with floating peat beds. It has dark peat stained water. This lake is full of small brown trout, up to 1lb.

The fishing is controlled by Rhayader and Elan Valley Angling Association. The lakes can be fished on the same ticket as the Claerwen reservoir