From the car park I walked back along the road a short way towards Bethesda and branched left on the contouring road to join the Gerlan road. I turned left up the narrow lane signed Ciltwllan to reach access land at the pumping station. A path heads eastwards into the Afon Caseg valley, becoming a good track as it passes settlement remains but becoming much less distinct beyond. There was a fine view across the valley to the Carnedd y Filiast ridge.

The map shows a path converging with the Afon Caseg but I couldn't see it and the terrain looked most uninviting, not a natural approach at all. I found it better to keep to the higher ground, and after a bit of very mild bog dodging I joined an intermittent track of sorts that arcs around the slopes and descends on the far side of a set of stone sheepfolds near the Afon Wen: this target location can clearly be seen ahead as a prominent line contouring around southwards to the base of Carreg y Gath and the entrance to the cwm.

Easily crossing the Afon Wen, the contouring line is an excellent path, shown on the Harvey map but not the OS, that hugs the lower slopes around to the base of Carreg y Gath and ascends into the lower reaches of the enclosed cwm alongside the Afon Caseg. This is an excellent entrance and has superb mountain scenery all around, a family of buzzards crying and soaring at the top of the crags and the enticing heart of the cwm still hidden around the corner.

A side stream coming down from Foel Grach via Cwm Bychan joins the river in a series of cascades and a small fall. Beyond this point the path all but peters out, the water run-off from the mountainous slopes producing large patches of emerald green boggy ground, and I dodged around a bit to find a fairly dry line. A pair of wild horses roamed around near the true foot of Yr Elen's east ridge.

Turning the bend clearing the wet ground, I came to a natural crossing point and switched to the right side of the infant river and ascended to a rounded moraine directly ahead, pausing to look at the expanding rearward view across the lower cwm. At the top of the moraine Ffynnon Caseg came into view a short way below, a more vegetated lake than one might expect in a mountain cwm, and I descended to walk around its shore.

The scene encompassing the lake and mountain cirque beyond is splendid, yet seems to be very seldom visited and was totally deserted today, the immediate approaches were almost totally trackless.

Now came the daunting prospect of the steep slog up from the lake to join the towering east ridge of Yr Elen above at roughly its mid point where it becomes interesting. Knuckling down for the grind, this turned out to be the hardest part in terms of effort.

Cresting the ridge, an exciting upward line presented itself, the rocks jutting outwards from the spine like an array of jagged teeth, but the climb is very much easier than it first appears: there is a visible path all the way that involves only occasional easy use of hands. Nevertheless it is an excellent ascent line and it was over all too quickly, I emerged suddenly onto the quite flat summit area just as the thick humid haze gained sway and reduced the distant views to pale ghostly outlines. The midges were about and I hastened over to the western cairn to catch the slight breeze and have a bite to eat and a rest.

Just a handful of walkers were on the summit plateau, and along with a small group later beyond Carnedd Llewelyn, these would be the only walkers I saw on this backpack. I walked around the rim of Cwm Caseg to the bwlch with a good aerial view of Ffynnon Caseg far below. On the summit plateau a helicopter had been circling around, and looking back as I descended, it came in to land on the plateau (or hover just above ground), its whirring blades now just visible above the rocks.

I ascended towards Carnedd Llewelyn and crossed the deserted large stony plateau to arrive at the summit, the air again too thick to afford any decent views - I could barely see Carnedd Dafydd. I descended north eastwards to the lip of Cwm Bychan and walked eastwards to a pool in the expanse of grassland to make my first pitch, leaving plenty of time to familiarize with the setup of the new tent.

I quickly realised the humidity of the air when the temperature started to drop: the flysheet was quite wet by around 19:00. In the evening a small herd of wild horses came to the pool to drink, quietly walking off to pastures new in the low light of the sinking sun.

Clarity returned to the sky overnight and the tent had a constant glow from the moon, but when striking camp I noticed a cloud formation taking shape and I predicted a repeat of the conditions yesterday - it turned out to be true. I returned to the main path and traversed Foel Grach and Carnedd Gwenllian, capturing some views before the haze arrived, and set off towards Yr Aryg.

The region around Yr Aryg, Bera Mawr and Bera Bach is always a joy to walk. Well away from the main Carneddau highway, they see few walkers and retain a strong atmosphere of wild Wales. These prominent upthrusts of huge boulders and broken rock that provide such interesting sport for clambers to their summits stand in bold relief against the backdrop of rough grassland and occasional boggy pools.

Today I passed by the foot of Yr Aryg's rock pile but climbed to the summit of Bera Bach where the views were still clear. The refreshing light breeze I had enjoyed so far today disappeared at the summit and a dense cloud of midges was in the air: one quick photo and I was off sharpish - it's surprising how fast one can descend from a summit of skewed boulders when a pressing need arises!.

Back in the breeze I continued to the next bwlch and the helicopter was back circling again, this time it descended to just above ground level near the bwlch as I was ascending Drosgl. When I arrived at the domed summit, sporting several cairns and a large shallow mound of stones, the thick haze had asserted itself and the high grey cloud prevailed, destroying any views. A trackless but easy descent led to a thin path on to the last summit of Gyrn Wigau.

I explored a new descent route today: from Gyrn Wigau I followed a thin grassy path roughly westwards, crossing what appears to be a contouring leat on the map but is now merely an obvious line of reeds, until it disappeared, leaving a short descent to a stone wall and sheepfold where there is a clear track on the line of the public footpath. Keeping a careful eye on the map, I followed this path northwards, becoming less and less distinct, to cross the infant Afon Ffrydlas and veering north westwards to the small stream of Ffos Rhufeiniaid. Just after this I joined the excellent track south west below the flanks of Moel Faban, arriving at a metal kissing gate in a wall, leading onto a track down to the road head that drops neatly to the road at Cilfodan.