Pen Pumlumon Arwystli
| Pen Pumlumon Arwystli | |||
| Cardiganshire, Montgomeryshire | |||
|---|---|---|---|
 Looking towards the Wye Valley from Pen Pumlumon Arwystli | |||
| Range: | Cambrian Mountains | ||
| Summit: | 2,431 feet SN815877 52°28’30"N, 3°44’45"W | ||
Pen Pumlumon Arwystli is the second highest point on the Plynlimon massif, a part of the Cambrian Mountains. Its summit marks the border between Cardiganshire to the west and Montgomeryshire to the east. It rises to 2,431 feet.
The summit is grassy, and is marked by three large ancient cairns. The views include Rhos Fawr, Drygarn Fawr, Pen y Garn to the south and Aran Fawddwy, Glasgwm, Tarrenhendre and Tarren y Gesail to the north.
The River Severn, the longest river in Britain, has its source on a lower boggy plateau to the east of the summit, whence in descends through Montgomeryshire and the Hafren Forest.
Name
Pumlumon is the Welsh-language name for Plynlimon, and gives a name to a number of the subsidiary peaks of the Plynlimon. (Plynlimon itself is distinguished as Pumlumon Fawr: "Great Plynlimon").
Arwystli was an ancient cantref around the headwaters of the River Severn. It was chiefly associated with the Kingdom of Powys, but was often fought over by the rulers of Powys and Gwynedd and by and the Norman Marcher Lords, and for hundreds of years Arwystli was the scene of many skirmishes between those groups.