Cwm Llugwy and Craig yr Ysfa 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 grade 1 scramble to the summit from Cwm Llugwy reservoir access track.
Cwm Llugwy and Craig yr Ysfa starts at about 294 m and gains 758 m over 5.0 km to 1,049 m on the track. It is steep from the start: the first kilometre climbs 153 m (15%). The steepest kilometre is the one ending at 4 km, which climbs 254 m at an average of 25%, with a 500 m stretch from 3.2 km at about 30%. It keeps climbing at 19% to the top. About 22% of the way is steeper than 1 in 5, so expect hands-on-knees going and a slow descent.
Cwm Llugwy and Craig yr Ysfa at a glance
| Distance | 5.0 km one way, to the top |
|---|---|
| Ascent | 780 m |
| Climb on the track | 758 m up, 7 m down on the way |
| Start and top of the track | 294 m to 1,049 m (summit 1,064 m) |
| Steepest 500 m | About 30%, from 3.2 km |
| Steeper than 1 in 5 | 22% of the way |
| Time up | 2h 20m by Naismith's rule |
| There and back | 3h 20m, down the same way |
| Grade | Scramble |
| Start | Cwm Llugwy reservoir access track |
| Start grid reference | SH 687 602 |
| Summit grid reference | SH 683 643 |
| Parking | No checked car park for this start; find lawful parking nearby |
Cwm Llugwy and Craig yr Ysfa map
The track from the start (green) to the summit (blue), with a marker at each kilometre.
Height profile and getting to the start
Near the start
- Public toilets0.3 km
- Public toilets0.3 km
- Public toilets0.3 km
- Gwern Gôf Isaf Campsite & Bunkhouses0.2 km
- Gwern Gof Uchaf Campsite1.6 km
From OpenStreetMap, within 2 km. Check opening times before you rely on them.
Download the Cwm Llugwy and Craig yr Ysfa GPX
Ascent only: plan your way down. A planning track, not checked on the ground; it doesn't show safe scrambling moves. Track data © OpenStreetMap contributors (ODbL), heights from a terrain model.
Cwm Llugwy and Craig yr Ysfa kilometre by kilometre
Height, climb and average gradient for each kilometre of the track, with a grid reference at the end of each one to check your position on the map.
| At | Height | Climb | Gradient | Grid ref |
|---|---|---|---|---|
| 1 km | 447 m | +153 m | 15% | SH 691 611 |
| 2 km | 552 m | +105 m | 10% | SH 695 620 |
| 3 km | 607 m | +55 m | 5% | SH 694 630 |
| 4 km | 861 m | +254 m | 25% steep | SH 691 638 |
| 5 km | 1,049 m | +187 m | 19% | SH 683 643 |
How long Cwm Llugwy and Craig yr Ysfa takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 1h 50m | 2h 40m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 2h 20m | 3h 20m |
| Relaxed 4 km/h, 12 min per 100 m up | 2h 50m | 4h 5m |
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 13:54 to be down before dark, allowing 3h 20m for the walk and an hour for stops.
- Tomorrow: sunrise 07:49, sunset 18:11. Start by 13:51 to be down before dark, allowing 3h 20m 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 Cwm Llugwy and Craig yr Ysfa: 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 Cwm Llugwy reservoir access track
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- Cwm Llugwy and Craig yr Ysfa via Carnedd Llywelyn up Foel Grach
- Cwm Llugwy and Craig yr Ysfa via Carnedd Llywelyn up Yr Elen
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 |
| Ogwen via Pen yr Helgi Du | 8.3 km one way | 879 m | 3h 10m | Scramble |
| 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 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 687 602, 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.
Cwm Llugwy and Craig yr Ysfa: questions and answers
How far is Cwm Llugwy and Craig yr Ysfa?
Cwm Llugwy and Craig yr Ysfa is 5.0 km one way to the summit of Carnedd Llewelyn, with 780 m of ascent. There and back by the same way is about 10.0 km.
How long does Cwm Llugwy and Craig yr Ysfa take?
About 2h 20m to the summit of Carnedd Llewelyn and 3h 20m 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 4h 5m for the round trip.
How steep is Cwm Llugwy and Craig yr Ysfa?
The steepest 500 m averages about 30%, starting 3.2 km from the start, and 22% of the way is steeper than 1 in 5. Cwm Llugwy and Craig yr Ysfa climbs 758 m in all on the track.
Where do you park for Cwm Llugwy and Craig yr Ysfa?
Cwm Llugwy and Craig yr Ysfa starts from Cwm Llugwy reservoir access track. The grid reference is SH 687 602. No checked car park for this start; find lawful parking nearby
Is Cwm Llugwy and Craig yr Ysfa 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 Cwm Llugwy and Craig yr Ysfa today?
By 13:54 at the latest. Sunset on Carnedd Llewelyn today is 18:14, Cwm Llugwy and Craig yr Ysfa takes about 3h 20m there and back, and that leaves an hour for stops. Start earlier in winter or if the forecast turns.
Is there a GPX for Cwm Llugwy and Craig yr Ysfa?
Yes. Download it from this page. It is an ascent-only planning track from the start to the summit, plotted on OpenStreetMap paths and not checked on the ground.