(both: plĭnlĭm`ən), Welsh Plumlumon Fawr, mountain, 2,468 ft (752 m) high, W Wales, on the Powys-Ceredigion border W of Llanidloes. It has three summits and is the source of the Wye, Severn, and other waters.
I YMATEB i lythyr Rhoda Bramhall yn gofyn ble mae Esgair Llyn: Os buasech yn cerdded o gyfeiriad Aberhosan tuag at Plynlimon Fach dros Moel Hyddgen a Rhos y Llyn; heibio Talbontdrain a Hengwm Cyfeiliog, mae Esgair Llyn ar goll yn y goedwig fel mae'r Hengwm.
From this charming mid-Wales market town it is good day's walk up through the Hafren Forest to the source of the Severn, which rises at an altitude of 2001 feet on boggy and marshy moorland at Plynlimon.
The route took runners over the Glyders, Carneddau, the Moelwyns and Rhinogydd, before going through the Plynlimon area, and Elan Valley, ending at Carreg Cennen Castle in the Brecon Beacons on day five.
Mountains (M) M1 Hebog mass M2 Snowdon mass M3 Glyder mass M4 Llywelyn mass M5 Arenig mass M6 Rhinog mass M7 Cadair Idris mass M8 Aran mass M9 Berwyn mass M10 Plynlimon M11 Radnor Forest M12 Mynydd Du M13 Fforest Fawr M14 Brecon Beacons M15 Black Mountains Hills (H) H1 Clwydian Range H2 Ll?
The route from Plynlimon, the source of the Severn, all the way to Shrewsbury contains rapids, as well as six-foot nettles and brambles on its banks andthe journey is one which organisers believe has not been attempted since the Bronze Age.