|} Plynlimon (anglicised from Pumlumon in Welsh, meaning "five peaks")'s the highest point of the Cambrian Mountains in Wales. It's a massif that dominates the countryside of northern Ceredigion. The highest point of the massif itself's Pen Pumlumon Fawr at 752 metres. Its other important peaks are Pen Pumlumon Arwystli and Y Garn. The longest river in Britain, the River Severn, has its source on the mountain, as do the rivers Wye and Rheidol. Folklore says there's a sleeping giant in Plynlimo… (More on Plynlimon)