Hidden away in remote mid-Wales, Pumlumon is more frequently visited by red kites and buzzards than by walkers. The region’s highest mountain at 752m/ 2,467ft, it’s one of the country’s principal hills after Yr Wyddfa (Snowdon) and Cadair Idris. Three major rivers – the Wye, the Severn and the Rheidol – have their sources on its slopes. Lacking the dramatic cliffs and crags found on other Welsh peaks it is, nevertheless, a walker’s hill, rewarding persistence and stamina with stunning views across Central Wales. The going is relatively gentle and navigation across this large area of access land is frequently aided by fences.
[1] Follow the track between farm buildings at Eisteddfa Gurig, which bears left before a gate misleadingly signed ‘All Walks’. Head uphill on a track past sheds (SN792839), after which it forks left to a crossroads by a plantation (SN787841).
[2] Bear right (SN787841) uphill. The track veers right after 900m (SN786847) but stay with the fence uphill for a further 400m to a corner (SN784851).
[3] Turn left through a gate to follow the plantation boundary west. Above the treeline, dips and rises bring you to Y Garn.
(A) Y Garn's 684m/2244ft summit cairn (SN775852) in Welsh means ‘The Cairn’ and provides excellent views across Nant-y-moch dam to Cardigan Bay.
[4] Return to [3] and then bear left, (north-easterly), following a fence across broad Pen y Drawsallt for 2km/1½ miles to Pumlumon Fawr (752m/2,474ft, SN789869).
(B) Views from the large summit cairn of Pumlumon Fawr are far-ranging: Cadair Idris and the Aran hills to the north, Brecon Beacons to the south and, on the clearest days, the Peak District far away in the east.
The fence guides you east a kilometre to Pumlumon Llygad-bychan (727m/2,385ft, SN799872) and its cairn and boundary stone. Continue in the same direction towards a gate in the next fence 300m ahead (your accompanying fence veers away right). You’ll pass the River Wye’s source (SN802872) 40m/131ft below you.
[5] Through the gate, another fence guides you east for a kilometre, past peat hags, towards Pumlumon Arwystli (741m/2,431ft, SN815877). The fence swings right of the rocky summit, where cairns provide shelter. Rejoin the fence, heading north but ignoring arrowed-inscribed boundary stones. Just beyond some pools (SN819894) the worst of the walk’s first bog can be avoided by circling it left.
[6] 300m beyond the bog, cross a stile (SN818897) and pass another pool to head a kilometre north-west, tracing the dog-legging fence on your left through peat to Carnfachbugeilyn (622m/2,041ft, SN826904).
Here you’ll find a small cairn and a big view across Llyn Clywedog reservoir.
500m to the south-east, quartz-capped twin cairns on Carn Biga can be visited by traversing the headwaters of the Nant y Barcud, before returning past the swampy source of the River Severn (SN824899) and back to [6].
[7] Head west across Bryn Cras. If a landmark is needed, aim for the prominent cairn (SN807896) visible in good weather less than a mile away; otherwise the rocky edges of beautiful Cwm Gwerin deserve exploration. Gentle slopes drop to the Afon Hengwm near a ruined farm (SN798894).
[8] Walking downstream isn’t easy – the map’s track materialises occasionally from bogs only to sink without trace (so take a lot of care here) – but the crag-sided valley is spacious, sheltered and peaceful. After crossing the Nant y Llyn (SN784891) – the infant River Rheidol – the track becomes better defined and is surfaced beyond Maesnant outdoor centre (SN775879). The little-used road carries you south, alongside Nant-y-Moch Reservoir. After a short uphill, bear left at a junction (SN 763864) for 2km/1½ miles, turning off left on a rough track (SN 758848) that leads through Y Garn’s forestry, to emerge at [2]. Descend the track ahead back to Eisteddfa Gurig.