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Covert Carneddau – Cwm Caseg, Carreg y Gath and Clogwyn y Heliwr

By Dave Roberts   

on August 14, 2016    No ratings yet.

Covert Carneddau – Cwm Caseg, Carreg y Gath and Clogwyn y Heliwr

Further Details

Route Summary:

This walk includes the Hewitt of Garnedd Uchaf (Carnedd Gwenllian)

This walk includes the 3 Nuttalls of Garnedd Uchaf (Carnedd Gwenllian), Bera Bach, Gyrn Wigau

Route Start Location:

15.62 km 801 m

Calculate the time using Naismith’s Rule and factor in your own pace.

Activivity Type: Hard Walk

Summits and Places on this Route


none noted


Remember that we cannot outline every single hazard on a walk – it’s up to you to be safe and competent. Read up on Mountain Safety , Navigation and what equipment you’ll need.

Parking :

Public Transport:

Traveline for UK Public Transport

Recommended Maps


Covert Carneddau – Cwm Caseg, Carreg y Gath and Clogwyn y Heliwr Ordnance Survey Map and GPX File Download

Download file for GPS

Covert Carneddau – Cwm Caseg, Carreg y Gath and Clogwyn y Heliwr

The Carneddau boast so many valleys and ridges, that even whwn you think you’ve done it all there’s always some corner left to explore. We were impressed with the epic nature of Cwm Caseg when we explored Yr Elen’s NE Ridge, and vowed to find any excuse to return. It’s a long walk in, not always clear, but almost immediately remote.

This walk sets off up a blunt ridge up onto the main Carneddau spine, and while we skipped Llewelyn on this instance, it would be a must on most occasions! Treat this route guide as an off-path and quiet route to Carnedd Llewelyn rather than a circuit in itself.

1 The walk starts off in Gerlan in Bethesda near the PO marked on the map. There are no such facilities here any more, and as parking is also an issue, you are advised to start from Bethesda. From Gerlan, continue up hill and take second left hand junction when the road forks (there’s a road sign here showing you that both routes are dead ends!). Follow this road, until it deteriorates into a track, ending eventually at the disused pumping station shown on the map, a derelict red brick building on the ground.


2. Once into the cwm, the route is steady and never too easy to follow! We kept higher up the slope, but a clear path follows a dry low ridge of land in the valley (marked by the right of way on the map) and is the easiest route to follow.  There are some really wet sections, but mostly easily avoided if you keep to the faint track.

3 Avoid the flatter valley bottom and keep left towards the slightly higher ground, and you’ll eventually reach the Afon Wen and a large collection of sheepfolds. Keep to the left of these and cross the stream easily, if you’ve managed to regain one of the faint tracks. On the other side of the stream, you may find a severely boggy section and you’ll need to walk upstream for a few metres to find a few large stones that make crossing easy. Contour around and you’ll find yourself after a few 100m at the start of the ascent.

You can easily ascend to Carreg y Gath from the stream, but the walk along makes a good point to stop.

4 The ascent is now by zig-zagging back up the slope, returning from the way you came. There’s no path, and you’ll need to judge keeping high while avoiding the crags above. You soon arrive at the grassy remains of the quarry track, which is more of a rough guideline alogn the hillside than a path. This zigs back on itself, before steeply continuing uphill. It will vanish before long, and you need to head due south towards the summit of Carreg y Gath on a steep and grassy slope.

5 The summit provides a fine viewpoint towards the upper reaches of Cwm Caseg, over to Yr Elen and back down the valley. There are sharp drops to the sides, making it a good photo-op.

5 A faint path along the grassy ridge of Clogwyn yr Heliwr leads the way uphill from here, with an option to skirt the edges or keep to the grassy summits. Nav skills will be needed in mist, and in fine visibility you’ll need to keep left of the scree on Foel Grach directly ahead. In fact, you should take the easiest route to the ridge, which we found was walking to the col between Foel Grach and Garnedd Uchaf.

We think this would make a better descent than a climb – and combining it with Yr Elen NE Ridge would make a satisfying and remote horseshoe walk.

6 From the ridge we headed off towards Garnedd Uchaf (Carnedd Gwenllian) and descended the Aryg Ridge, a path that’s easy to lose and requiring some compass work in mist. It’s much better to find the footpath that contours above Cwm Caseg, as that’s easier to follow. The ridge becomes flatter after Yr Aryg, and was particularly boggy this time around. While you’re here, you may as well head off for a bit of scrambling on Bera Mawr, which is lower than Bera Bach but certainly larger in scale.

Heading to the right of Bera Bach, you can follow easy slopes to yet another plateau area. Turn left here, continuing around the base of Bera Bach and ignoring a more obvious wide track, until you hit a footpath that contours along the hillside above Cwm Caseg.


7 Continue on the footpath, which is narrow, until it turns around to the right. Keep on it for a few 100m before heading left along a faint path towards Gyrn Wigau. This isn’t much of a summit, but provides great views back towards the Carneddau.

8 Continue along the faint path, which descends steadily to reach a wall and a stile. Cross the wall and follow the good path towards the start of the Cwm Caseg track you started off on earlier and retrace your tracks back to the start.


Dave Roberts founded Walk Eryri in 2004, with the aim of providing routes that are off the beaten track. Walk Eryri is now part of Mud and Routes which continues to provide more off beat routes and walks in Snowdonia and beyond. Dave has been exploring the hills of Eryri for over thirty years, and is a qualified Mountain Leader. Dave also established Walk up Snowdon, Walk up Scafell Pike and Walk up Ben Nevis just to mention a few.
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