Cwm Mynach and eastern ridge up Crib-y-rhiw: route map, distance and time
681 m · Barmouth to Betws-y-Coed and Bala
A hard mountain walk to the summit from Dolmelynllyn car park, Ganllwyd.
The Cwm Mynach and eastern ridge starts at about 54 m and gains 1,131 m over 13.8 km to 648 m on the track. The first kilometre climbs 41 m. The steepest kilometre is the one ending at 3 km, which climbs 187 m at an average of 19%, with a 500 m stretch from 12.1 km at about 34%. The final 0.8 km eases to the top. About 12% of the way is steeper than 1 in 5, so expect hands-on-knees going and a slow descent.
Cwm Mynach and eastern ridge at a glance
| Distance | 13.8 km one way, to the top |
|---|---|
| Climb on the track | 1,131 m up, 537 m down on the way |
| Start and top of the track | 50 m to 666 m (summit 681 m) |
| Steepest 500 m | About 34%, from 12.1 km |
| Steeper than 1 in 5 | 12% of the way |
| Grade | Hard |
| Start | Dolmelynllyn car park, Ganllwyd, LL40 2TF |
| Start grid reference | SH 726 243 |
| Summit grid reference | SH 663 248 |
| Parking | Dolmelynllyn car park, Ganllwyd (SH727243) |
Cwm Mynach and eastern ridge 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 Cwm Mynach and eastern ridge 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 Mynach and eastern ridge 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 | 95 m | +41 m | 4% | SH 724 241 |
| 2 km | 240 m | +145 m | 14% | SH 719 234 |
| 3 km | 427 m | +187 m | 19% | SH 714 228 |
| 4 km | 586 m | +159 m | 16% | SH 705 230 |
| 5 km | 511 m | -74 m | -7% | SH 698 230 |
| 6 km | 417 m | -94 m | -9% | SH 693 222 |
| 7 km | 309 m | -109 m | -11% | SH 690 217 |
| 8 km | 180 m | -129 m | -13% | SH 686 215 |
| 9 km | 207 m | +27 m | 3% | SH 687 224 |
| 10 km | 254 m | +47 m | 5% | SH 684 230 |
| 11 km | 316 m | +62 m | 6% | SH 677 232 |
| 12 km | 481 m | +165 m | 16% | SH 669 234 |
| 13 km | 627 m | +146 m | 15% | SH 666 241 |
| 13.8 km | 648 m | +21 m | 3% | SH 663 248 |
How long the Cwm Mynach and eastern ridge takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 3h 50m | 6h 5m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 4h 40m | 7h 25m |
| Relaxed 4 km/h, 12 min per 100 m up | 5h 45m | 9h 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.
Crib-y-rhiw summit weather for this route
There is no recent summit forecast cached for Crib-y-rhiw right now. The main Crib-y-rhiw page loads the live forecast when you open it. Open the live Crib-y-rhiw forecast.
Before you go, also check: MWIS Snowdonia forecast · Met Office mountain forecast.
About Crib-y-rhiw
More about Crib-y-rhiw, with the live forecast.
Challenges that include Crib-y-rhiw
More walks from Dolmelynllyn car park, Ganllwyd
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- Ganllwyd and Rhaeadr Ddu forest paths up Y Garn
- Cwm Mynach via Diffwys up Diffwys West Top
Other routes up Crib-y-rhiw
| Route | Distance | Ascent | Time up | Grade |
|---|---|---|---|---|
| Talybont via the southern ridge | 10.3 km one way | 680 m | 3h 10m | Hard |
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 726 243, the summit at SH 663 248), 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 Mynach and eastern ridge: questions and answers
How far is the Cwm Mynach and eastern ridge?
The Cwm Mynach and eastern ridge is 13.8 km one way to the summit of Crib-y-rhiw. There and back by the same way is about 27.6 km.
How steep is the Cwm Mynach and eastern ridge?
The steepest 500 m averages about 34%, starting 12.1 km from the start, and 12% of the way is steeper than 1 in 5. The Cwm Mynach and eastern ridge climbs 1,131 m in all on the track.
Where do you park for the Cwm Mynach and eastern ridge?
The Cwm Mynach and eastern ridge starts from Dolmelynllyn car park, Ganllwyd (postcode LL40 2TF). The grid reference is SH 726 243. Dolmelynllyn car park, Ganllwyd (SH727243)
Is the Cwm Mynach and eastern ridge 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.
Is there a GPX for the Cwm Mynach and eastern ridge?
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.