The walk from Ogwen climbs Pen yr Ole Wen first. It then follows the high ground over Carnedd Dafydd to Carnedd Llewelyn, the highest of the Carneddau.
The Carneddau are hard to navigate in thick mist, and the far reaches can be boggy.
Measure the round on your map before you go.
The summits and the steep start
The British Mountaineering Council (BMC) lists seven Carneddau summits above 3,000 feet, with Carnedd Gwenllian marked “if included”. These are its heights:
- Pen yr Ole Wen: 978 m
- Carnedd Dafydd: 1,044 m
- Carnedd Llewelyn: 1,064 m
- Yr Elen: 962 m
- Foel Grach: 976 m
- Carnedd Gwenllian: 926 m
- Foel-fras: 942 m
Pen yr Ole Wen comes first and is steep, loose scree in places. A runner in the BMC’s Welsh 3000s guide calls it the hardest part of the route for anyone going south to north.
You can easily lose the path if you are not careful, particularly in mist.
Expect steep, loose ground from the first climb, and keep checking that you are still on the path.
Carnedd Llewelyn: where to decide
Beyond Pen yr Ole Wen the route stays high, over Carnedd Dafydd to Carnedd Llewelyn.
Carnedd Llewelyn is the natural place to decide whether the day goes on. You have reached the highest of the Carneddau, and everything beyond it is further from Ogwen.
Mist and the map
The same runner in the BMC’s guide says the Carneddau is hard to navigate in thick mist.
The Met Office’s poor-visibility hazard means visibility is often 50 metres or less, from low cloud or falling or blowing snow. On a featureless plateau like the Carneddau, that leaves little to steer by.
Distances become hard to judge, and such conditions need good navigational skills.
On broad high ground in cloud, a map and compass are what keep you on the route. The Ordnance Survey sheet for Snowdonia shows which one you need. Read the forecast through Snowdonia mountain weather before you commit.
The boggy far reaches
North of Carnedd Llewelyn lie Foel Grach, Carnedd Gwenllian and Foel-fras. The far reaches of the Carneddau can be boggy.
The National Trust owns 21,000 acres of these mountains, the Carneddau and Glyderau together. It describes steep, rocky, boggy and uneven terrain in places.
From Foel-fras, the BMC’s guide drops down to Bwlch y Ddeufaen or to the ground above Abergwyngregyn. Neither exit brings you back to Ogwen, so a walk that goes this far needs its own lift home.
Take a head torch, just in case. A head torch for Snowdonia is a small item to pack for a day that might run late.
Plan your way down before you go
Have a back-up plan to bail out, and think about how you would get back if you had to leave the route at Ogwen.
Choose the way down on the map at home, not on the ridge.
The Ogwen Valley Mountain Rescue Organisation chose one descent for its event. It drops from Pen yr Ole Wen to the farm at Tal y Llyn, which it calls slightly longer but an easier descent and less environmentally damaging.
From the farm, a path alongside Llyn Ogwen leads back to the car park.
Write down your decision points before you set off:
- Pen yr Ole Wen: if the path is hard to hold in mist, do not push on.
- Carnedd Dafydd: check the cloud and the wind before the long stretch to Carnedd Llewelyn.
- Carnedd Llewelyn: go back the way you came, or commit to the far reaches.
- Foel-fras: one of the two exits, with transport arranged.
The rescue team is a volunteer service for the Ogwen valley, the Glyderau and the Carneddau, on call 24 hours a day.
It is not a substitute for a plan, and staying safe in Snowdonia covers what to do first.
Getting to Ogwen
Ogwen is a base for the Carneddau and the Glyderau. Double yellow lines run along parts of the A5 here, and you cannot park on them, including on the pavement.
Spaces fill quickly in the spring and summer holidays. The Ogwen Centre car park is small and takes only card or contactless payment.
On a busy day, leave the car in Bethesda and take the bus. Use the buses from Bethesda when Ogwen is full.
- T10 TrawsCymru: links Bangor, Bethesda and Betws y Coed and stops at Ogwen.
- Bws Ogwen: a nine-seater electric bus between Bethesda and Ogwen.
- Bethesda football club car park: the place to park if you use public transport. The gate is closed from 22:00 to 07:00, so be back before it shuts.
More on car parks is in parking in Snowdonia.
Tryfan, Glyder Fawr and Cwm Idwal start from the same valley: see Tryfan, Glyder Fawr and Cwm Idwal. The Welsh 3000s challenge finishes on Foel-fras.
We compile and explain public route and safety information. We guide nobody and sell nothing on the hill.
The morning you go
Open the Met Office mountain forecast for Snowdonia and find the line headed chance of cloud-free hill tops. If it is low for the hours you will be on the tops, the Carneddau are a poor choice for that day.
