Ogwen via Pen yr Helgi Du up Carnedd Llewelyn: route map, distance and time
1,064 m · Snowdonia
Carnedd Llewelyn is the highest summit of the Carneddau, a broad, stony plateau at the centre of Snowdonia's northern range.
A path over Pen yr Helgi Du, down into Bwlch Eryl Farchog and up the rocky ridge to the summit.
Ogwen via Pen yr Helgi Du at a glance
| Distance | 8.3 km one way, to the top |
|---|---|
| Ascent | 879 m |
| Time up | 3h 10m by Naismith's rule |
| There and back | 4h 45m, down the same way |
| Grade | Scramble |
| Start | Glan Dena, Ogwen valley |
| Start grid reference | SH 668 605 |
| Summit grid reference | SH 683 643 |
Ogwen via Pen yr Helgi Du map
The start (green) and the summit (blue). Peakify has no GPX track for this route yet, so follow the description and your map.
Height profile and getting to the start
Near the start
- Ogwen Tea Bar1.9 km
- Public toilets0.5 km
- Public toilets1.8 km
- Public toilets1.8 km
- Gwern Gof Uchaf Campsite0.5 km
- Gwern Gôf Isaf Campsite & Bunkhouses1.9 km
- YHA Idwal2.0 km
From OpenStreetMap, within 2 km. Check opening times before you rely on them.
How long Ogwen via Pen yr Helgi Du takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 2h 35m | 3h 55m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 3h 10m | 4h 45m |
| Relaxed 4 km/h, 12 min per 100 m up | 3h 50m | 5h 55m |
Times leave out stops. Coming down the same way, the table counts the ascent once; steep descents on rough ground can be as slow as the climb.
- Today: sunrise 07:48, sunset 18:14. Start by 12:29 to be down before dark, allowing 4h 45m for the walk and an hour for stops.
- Tomorrow: sunrise 07:49, sunset 18:11. Start by 12:26 to be down before dark, allowing 4h 45m for the walk and an hour for stops.
Carnedd Llewelyn summit weather for this route
-
Marginal Today Sunday 18 October
Overcast, up to 4°C at the summit, feeling as cold as -5°C, summit wind 25 mph gusting 32 mph, 21% chance of rain. Rated Marginal. Sunrise 07:48, sunset 18:14.
-
Marginal Tomorrow Monday 19 October
Moderate drizzle, up to 5°C at the summit, feeling as cold as -4°C, summit wind 37 mph gusting 47 mph, 73% chance of rain. Rated Marginal. Sunrise 07:49, sunset 18:11.
Best day of the next seven for Ogwen via Pen yr Helgi Du: Sunday 18 October, with summit gusts around 32 mph and a 21% chance of rain.
Cloud inversion tomorrow morning: 2% (Low), best around 05:00. 7-day inversion outlook.
Hour-by-hour Carnedd Llewelyn forecast · 14-day forecast · Is it safe to climb Carnedd Llewelyn?
Before you go, also check: MWIS Snowdonia forecast · Met Office mountain forecast.
What to take today
- An insulated jacket, hat and warm gloves: it feels like -5°C on top.
- A waterproof jacket. It can rain on the tops in any forecast.
- A windproof layer, and poles for balance in gusts to 32 mph.
- Microspikes for icy paths. In snow, an ice axe and crampons and the skills to use them.
- Map and compass, and the skills to use them. A phone is a backup, not a plan.
- A head torch, food, water, a charged phone and a small first aid kit.
About Carnedd Llewelyn
Carnedd Llewelyn is the highest summit of the Carneddau, a broad, stony plateau at the centre of Snowdonia's northern range. More about Carnedd Llewelyn, with the live forecast.
On the lists: Furth, Hewitt, Nuttall, Marilyn, county top.
Extend the walk: tops near the summit
- Yr Elen (962 m), 1.2 km north-west
- Foel Grach (975 m), 1.6 km north
- Pen yr Helgi Du (833 m), 1.9 km south-east
- Carnedd Dafydd (1,044 m), 2.5 km south-west
- Garnedd Uchaf (925 m), 2.6 km north
- Foel Meirch (799 m), 2.6 km west
Challenges that include Carnedd Llewelyn
- Welsh 3000s · 15
- Welsh 100 Challenge · 100
- Welsh 1000m Peaks · 5
- Snowdonia 900m Peaks · 16
- Carneddau Traverse · 7
- Paddy Buckley Round · 47
- Furths · 34
- Hewitts · 523
- Nuttalls · 442
- Marilyns · 1,555
More walks from Glan Dena, Ogwen valley
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- Ogwen via Cwm Lloer and Pen yr Ole Wen up Carnedd Dafydd
- Glan Dena via Cwm Lloer up Pen yr Ole Wen
Other routes up Carnedd Llewelyn
| Route | Distance | Ascent | Time up | Grade |
|---|---|---|---|---|
| Ogwen via Carnedd Dafydd | 7.4 km one way | 910 m | 3h 0m | Moderate |
| South-west ridge from Ogwen and Carneddau ridge | 6.5 km one way | 940 m | 2h 50m | Hard |
| Gerlan via Yr Elen north-west ridge | 6.7 km one way | 890 m | 2h 50m | Hard |
| Cwm Eigiau via the eastern Foel Grach ridge | 12.0 km one way | 830 m | 3h 45m | Hard |
| Rachub via Drosgl and Yr Aryg flanks, via Bera Bach | 9.8 km one way | 830 m | 3h 20m | Hard |
| Bwlch y Ddeufaen via Drum and northern ridge | 11.1 km one way | 840 m | 3h 35m | Hard |
| Llanfairfechan via Drum and northern ridge | 11.7 km one way | 1,000 m | 4h 0m | Hard |
| Abergwyngregyn via Drum via Drum and northern ridge | 11.3 km one way | 960 m | 3h 50m | Hard |
| East Ridge via Ffynnon Lloer and Carneddau ridge | 7.4 km one way | 920 m | 3h 0m | Scramble |
| Crib Lem / Llech Ddu Spur and Carnedd Dafydd | 9.2 km one way | 1,000 m | 3h 30m | Scramble |
| Cwm Llugwy and Craig yr Ysfa | 5.0 km one way | 780 m | 2h 20m | Scramble |
| Cwm Eigiau via Bwlch Eryl Farchog and Craig yr Ysfa | 9.7 km one way | 930 m | 3h 30m | Scramble |
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 668 605, the summit at SH 683 643), what happened and how many are in your group. If you have no signal for a call, a text to 999 works once you have registered your phone with emergencySMS: text "register" to 999 before you go.
Ogwen via Pen yr Helgi Du: questions and answers
How far is Ogwen via Pen yr Helgi Du?
Ogwen via Pen yr Helgi Du is 8.3 km one way to the summit of Carnedd Llewelyn, with 879 m of ascent. There and back by the same way is about 16.6 km.
How long does Ogwen via Pen yr Helgi Du take?
About 3h 10m to the summit of Carnedd Llewelyn and 4h 45m there and back by Naismith's rule (5 km/h plus 10 minutes per 100 m of ascent), before stops. A relaxed group takes nearer 5h 55m for the round trip.
Where do you park for Ogwen via Pen yr Helgi Du?
Ogwen via Pen yr Helgi Du starts from Glan Dena, Ogwen valley. The grid reference is SH 668 605.
Is Ogwen via Pen yr Helgi Du suitable for beginners?
No. It is a scramble: you use your hands on rock, often with big drops below. Go with someone experienced, on a dry and calm day, or take Ogwen via Carnedd Dafydd instead.
What time should I start Ogwen via Pen yr Helgi Du today?
By 12:29 at the latest. Sunset on Carnedd Llewelyn today is 18:14, Ogwen via Pen yr Helgi Du takes about 4h 45m there and back, and that leaves an hour for stops. Start earlier in winter or if the forecast turns.
Is there a GPX for Ogwen via Pen yr Helgi Du?
Not yet. The Peakify iPhone app can plan the route and export a GPX (Peakify Pro).