Llwybr y Carw / Afon Las up Y Garn (Snowdonia): route map, distance and time
947 m · Snowdonia
Y Garn is a pointed Glyderau summit above Llyn Idwal, with a classic view down to the Ogwen valley and Tryfan.
A hard mountain walk to the summit from Gwastadnant / Afon Las public footpath entrance.
Llwybr y Carw / Afon Las starts at about 150 m and gains 766 m over 3.6 km to 913 m on the track. It is steep from the start: the first kilometre climbs 363 m (36%). The steepest kilometre is the one ending at 1 km, which climbs 363 m at an average of 36%, with a 500 m stretch from 0.4 km at about 43%. It keeps climbing at 21% to the top. About 56% of the way is steeper than 1 in 5, so expect hands-on-knees going and a slow descent.
Llwybr y Carw / Afon Las at a glance
| Distance | 3.6 km one way, to the top |
|---|---|
| Ascent | 800 m |
| Climb on the track | 766 m up, 0 m down on the way |
| Start and top of the track | 150 m to 916 m (summit 947 m) |
| Steepest 500 m | About 43%, from 0.4 km |
| Steeper than 1 in 5 | 56% of the way |
| Time up | 2h 5m by Naismith's rule |
| There and back | 2h 45m, down the same way |
| Grade | Hard |
| Start | Gwastadnant / Afon Las public footpath entrance, LL55 4UF |
| Start grid reference | SH 615 577 |
| Summit grid reference | SH 630 595 |
| Parking | Nant Peris park and ride car park; the postcode is approximate |
Llwybr y Carw / Afon Las 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
From OpenStreetMap, within 2 km. Check opening times before you rely on them.
Download the Llwybr y Carw / Afon Las 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.
Llwybr y Carw / Afon Las 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 | 513 m | +363 m | 36% steep | SH 623 580 |
| 2 km | 706 m | +193 m | 19% | SH 632 584 |
| 3 km | 781 m | +75 m | 8% | SH 633 590 |
| 3.6 km | 913 m | +132 m | 21% steep | SH 630 595 |
How long Llwybr y Carw / Afon Las takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 1h 40m | 2h 15m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 2h 5m | 2h 45m |
| Relaxed 4 km/h, 12 min per 100 m up | 2h 30m | 3h 25m |
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 14:29 to be down before dark, allowing 2h 45m for the walk and an hour for stops.
- Tomorrow: sunrise 07:50, sunset 18:12. Start by 14:27 to be down before dark, allowing 2h 45m for the walk and an hour for stops.
Y Garn summit weather for this route
-
Good Today Sunday 18 October
Overcast, up to 5°C at the summit, feeling as cold as -4°C, summit wind 24 mph gusting 30 mph, 0% chance of rain. Rated Good. Sunrise 07:48, sunset 18:14.
-
Poor Tomorrow Monday 19 October
Moderate drizzle, up to 6°C at the summit, feeling as cold as -2°C, summit wind 43 mph gusting 54 mph, 90% chance of rain. Rated Poor. Sunrise 07:50, sunset 18:12.
Best day of the next seven for Llwybr y Carw / Afon Las: Sunday 18 October, with summit gusts around 30 mph and a 0% chance of rain.
Cloud inversion tomorrow morning: 1% (Low), best around 06:00. 7-day inversion outlook.
Hour-by-hour Y Garn forecast · 14-day forecast · Is it safe to climb Y Garn?
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 -4°C on top.
- A waterproof jacket. It can rain on the tops in any forecast.
- 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 Y Garn
Y Garn is a pointed Glyderau summit above Llyn Idwal, with a classic view down to the Ogwen valley and Tryfan. More about Y Garn, with the live forecast.
On the lists: Furth, Hewitt, Nuttall, Marilyn.
Extend the walk: tops near the summit
- Foel-goch (831 m), 1.7 km north
- Glyder Fawr (1,001 m), 2 km south-east
- Mynydd Perfedd (813 m), 2.4 km north
- Elidir Fawr (924 m), 2.6 km north-west
- Castell y Gwynt (972 m), 2.7 km south-east
- Glyder Fach (994 m), 2.9 km south-east
Challenges that include Y Garn
- Welsh 3000s · 15
- Welsh 100 Challenge · 100
- Snowdonia 900m Peaks · 16
- Welsh Skyline · 9
- Paddy Buckley Round · 47
- Furths · 34
- Hewitts · 523
- Nuttalls · 442
- Marilyns · 1,555
More walks from Gwastadnant / Afon Las public footpath entrance
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- Afon Las from Nant Peris and plateau traverse up Glyder Fach
- Afon Las from Nant Peris up Glyder Fawr
Other routes up Y Garn
| Route | Distance | Ascent | Time up | Grade |
|---|---|---|---|---|
| Ogwen via Llyn Clyd | 4.4 km one way | 741 m | 2h 5m | Hard |
| North East Ridge | 2.6 km one way | 640 m | 1h 35m | Hard |
| Devil's Kitchen / Twll Du | 4.3 km one way | 670 m | 2h 0m | Hard |
| Elidir Fawr, Mynydd Perfedd and Foel-goch | 7.5 km one way | — | — | Hard |
| Marchlyn via Elidir Fawr and Mynydd Perfedd | 7.6 km one way | 870 m | 3h 0m | Hard |
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 615 577, the summit at SH 630 595), 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.
Llwybr y Carw / Afon Las: questions and answers
How far is Llwybr y Carw / Afon Las?
Llwybr y Carw / Afon Las is 3.6 km one way to the summit of Y Garn, with 800 m of ascent. There and back by the same way is about 7.2 km.
How long does Llwybr y Carw / Afon Las take?
About 2h 5m to the summit of Y Garn and 2h 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 3h 25m for the round trip.
How steep is Llwybr y Carw / Afon Las?
The steepest 500 m averages about 43%, starting 0.4 km from the start, and 56% of the way is steeper than 1 in 5. Llwybr y Carw / Afon Las climbs 766 m in all on the track.
Where do you park for Llwybr y Carw / Afon Las?
Llwybr y Carw / Afon Las starts from Gwastadnant / Afon Las public footpath entrance (postcode LL55 4UF). The grid reference is SH 615 577. Nant Peris park and ride car park; the postcode is approximate
Is Llwybr y Carw / Afon Las suitable for beginners?
Not as a first mountain. Peakify grades it Hard: steep, rough ground where a slip matters. Build up on an easier route first.
What time should I start Llwybr y Carw / Afon Las today?
By 14:29 at the latest. Sunset on Y Garn today is 18:14, Llwybr y Carw / Afon Las takes about 2h 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 Llwybr y Carw / Afon Las?
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.