Wikipedia
Plynlimon
Plynlimon (anglicised from Pumlumon in Welsh, meaning "five peaks") is the highest point of the Cambrian Mountains in Wales, and the highest point in Mid Wales. It is a massif that dominates the countryside of northern Ceredigion.
The highest point of the massif itself is Pen Pumlumon Fawr at . Its other important peaks are Pen Pumlumon Arwystli, Y Garn, Pen Pumlumon Llygad-bychan and Pumlumon Fach.
The longest river in Britain, the River Severn, has its source on the mountain, as do the rivers Wye and Rheidol.
Folklore says there is a sleeping giant in Plynlimon.