1. Reservoir supplying water to Aberystwyth and area since 1883. Susan Evans, RCAHMW, 1998.

2. Llyn Llygad Rheidol lake at base of Pumlimon Fawr. Lake curtained by rock outcrop to south and west. Fed by Nant y Llyn. Was formerly a natural lake but has been enlarged by damming. R.S. Jones, Cambrain Archaeological Projects, 2004.