Ogwen via Y Garn and Mynydd Perfedd up Elidir Fawr: route map, distance and time
924 m · Snowdonia
Elidir Fawr is the western end of the Glyderau in Snowdonia, a large mountain above the Dinorwig quarries and the reservoir of Marchlyn Mawr.
A hard mountain walk to the summit from Ogwen Cottage.
Ogwen via Y Garn and Mynydd Perfedd starts at about 307 m and gains 879 m over 6.6 km to 888 m on the track. The first kilometre climbs 129 m. The steepest kilometre is the one ending at 2 km, which climbs 333 m at an average of 33%, with a 500 m stretch from 1 km at about 41%. It keeps climbing at 20% to the top. About 29% of the way is steeper than 1 in 5, so expect hands-on-knees going and a slow descent.
Ogwen via Y Garn and Mynydd Perfedd at a glance
| Distance | 6.6 km one way, to the top |
|---|---|
| Ascent | 920 m |
| Climb on the track | 879 m up, 302 m down on the way |
| Start and top of the track | 308 m to 913 m (summit 924 m) |
| Steepest 500 m | About 41%, from 1 km |
| Steeper than 1 in 5 | 29% of the way |
| Time up | 2h 50m by Naismith's rule |
| There and back | 4h 10m, down the same way |
| Grade | Hard |
| Start | Ogwen Cottage, LL57 3LZ |
| Start grid reference | SH 649 603 |
| Summit grid reference | SH 611 612 |
| Parking | Llyn Ogwen / Ogwen Centre car park; the postcode is approximate |
Ogwen via Y Garn and Mynydd Perfedd 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 Ogwen via Y Garn and Mynydd Perfedd 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.
Ogwen via Y Garn and Mynydd Perfedd 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 | 436 m | +129 m | 13% | SH 641 600 |
| 2 km | 769 m | +333 m | 33% steep | SH 633 599 |
| 3 km | 841 m | +73 m | 7% | SH 629 598 |
| 4 km | 745 m | -96 m | -10% | SH 625 607 |
| 5 km | 735 m | -10 m | -1% | SH 624 616 |
| 6 km | 762 m | +27 m | 3% | SH 617 614 |
| 6.6 km | 888 m | +126 m | 20% steep | SH 611 613 |
How long Ogwen via Y Garn and Mynydd Perfedd takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 2h 20m | 3h 25m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 2h 50m | 4h 10m |
| Relaxed 4 km/h, 12 min per 100 m up | 3h 30m | 5h 10m |
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 13:04 to be down before dark, allowing 4h 10m for the walk and an hour for stops.
- Tomorrow: sunrise 07:50, sunset 18:12. Start by 13:02 to be down before dark, allowing 4h 10m for the walk and an hour for stops.
Elidir Fawr 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, 21% chance of rain. Rated Good. Sunrise 07:48, sunset 18:14.
-
Marginal Tomorrow Monday 19 October
Moderate drizzle, up to 6°C at the summit, feeling as cold as -1°C, summit wind 39 mph gusting 49 mph, 73% chance of rain. Rated Marginal. Sunrise 07:50, sunset 18:12.
Best day of the next seven for Ogwen via Y Garn and Mynydd Perfedd: Sunday 18 October, with summit gusts around 30 mph and a 21% chance of rain.
Cloud inversion tomorrow morning: 3% (Low), best around 05:00. 7-day inversion outlook.
Hour-by-hour Elidir Fawr forecast · 14-day forecast · Is it safe to climb Elidir Fawr?
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.
- A windproof layer, and poles for balance in gusts to 30 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 Elidir Fawr
Elidir Fawr is the western end of the Glyderau in Snowdonia, a large mountain above the Dinorwig quarries and the reservoir of Marchlyn Mawr. More about Elidir Fawr, with the live forecast.
On the lists: Furth, Hewitt, Nuttall, Marilyn.
Extend the walk: tops near the summit
- Mynydd Perfedd (813 m), 1.3 km north-east
- Carnedd y Filiast (821 m), 1.7 km north-east
- Foel-goch (831 m), 1.7 km east
- Carnedd y Filiast North Top (720 m), 2 km north
- Y Garn (947 m), 2.6 km south-east
Challenges that include Elidir Fawr
- 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 Ogwen Cottage
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- South-west ridge from Ogwen and Carneddau ridge up Carnedd Dafydd
- South-west ridge from Ogwen and Carneddau ridge up Carnedd Llewelyn
- Devil's Kitchen / Twll Du and plateau traverse up Glyder Fach
- Senior's Gully and Ridge and plateau traverse up Glyder Fach
- Y Gribin and plateau traverse up Glyder Fach
- Bristly Ridge up Glyder Fach
- Devil's Kitchen / Twll Du up Glyder Fawr
- Senior's Gully and Ridge up Glyder Fawr
- Y Gribin up Glyder Fawr
- Bristly Ridge and plateau traverse up Glyder Fawr
- South-west ridge from Ogwen up Pen yr Ole Wen
- North East Ridge up Y Garn
Other routes up Elidir Fawr
| Route | Distance | Ascent | Time up | Grade |
|---|---|---|---|---|
| Nant Peris via the Afon Dudodyn | 3.4 km one way | 810 m | 2h 0m | Moderate |
| Marchlyn via Elidir Fach | 3.5 km one way | 560 m | 1h 40m | Hard |
| Marchlyn via Mynydd Perfedd | 5.9 km one way | 670 m | 2h 20m | Hard |
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 649 603, the summit at SH 611 612), 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 Y Garn and Mynydd Perfedd: questions and answers
How far is Ogwen via Y Garn and Mynydd Perfedd?
Ogwen via Y Garn and Mynydd Perfedd is 6.6 km one way to the summit of Elidir Fawr, with 920 m of ascent. There and back by the same way is about 13.2 km.
How long does Ogwen via Y Garn and Mynydd Perfedd take?
About 2h 50m to the summit of Elidir Fawr and 4h 10m 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 10m for the round trip.
How steep is Ogwen via Y Garn and Mynydd Perfedd?
The steepest 500 m averages about 41%, starting 1 km from the start, and 29% of the way is steeper than 1 in 5. Ogwen via Y Garn and Mynydd Perfedd climbs 879 m in all on the track.
Where do you park for Ogwen via Y Garn and Mynydd Perfedd?
Ogwen via Y Garn and Mynydd Perfedd starts from Ogwen Cottage (postcode LL57 3LZ). The grid reference is SH 649 603. Llyn Ogwen / Ogwen Centre car park; the postcode is approximate
Is Ogwen via Y Garn and Mynydd Perfedd 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, such as Nant Peris via the Afon Dudodyn.
What time should I start Ogwen via Y Garn and Mynydd Perfedd today?
By 13:04 at the latest. Sunset on Elidir Fawr today is 18:14, Ogwen via Y Garn and Mynydd Perfedd takes about 4h 10m 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 Y Garn and Mynydd Perfedd?
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.