Cwm Mynach eastern ascent up Y Garn (Snowdonia): route map, distance and time
629 m · Snowdonia
Y Garn is a 629 m Hewitt, Nuttall and Marilyn east of the Rhinogydd in southern Snowdonia, a quiet summit above the Mawddach valley.
A hard mountain walk to the summit from Cwm Mynach public forest path.
Cwm Mynach eastern ascent starts at about 320 m and gains 317 m over 2.8 km to 608 m on the track. The first 2 km are the easy part, averaging 10%. The steepest kilometre is the one ending at 2.8 km, which climbs 103 m at an average of 13%, with a 500 m stretch from 1.1 km at about 18%. That last pull ends at the summit. About 11% of the way is steeper than 1 in 5, so expect hands-on-knees going and a slow descent.
Cwm Mynach eastern ascent at a glance
| Distance | 2.8 km one way, to the top |
|---|---|
| Ascent | 340 m |
| Climb on the track | 317 m up, 28 m down on the way |
| Start and top of the track | 306 m to 608 m (summit 629 m) |
| Steepest 500 m | About 18%, from 1.1 km |
| Steeper than 1 in 5 | 11% of the way |
| Time up | 1h 10m by Naismith's rule |
| There and back | 1h 40m, down the same way |
| Grade | Hard |
| Start | Cwm Mynach public forest path |
| Start grid reference | SH 690 218 |
| Summit grid reference | SH 702 230 |
| Parking | No checked car park for this start; find lawful parking nearby |
Cwm Mynach eastern ascent map
The track from the start (green) to the summit (blue), with a marker at each kilometre.
Height profile and getting to the start
Download the Cwm Mynach eastern ascent 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 eastern ascent 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 | 418 m | +98 m | 10% | SH 693 221 |
| 2 km | 505 m | +87 m | 9% | SH 697 229 |
| 2.8 km | 608 m | +103 m | 13% | SH 702 230 |
How long Cwm Mynach eastern ascent takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 0h 55m | 1h 25m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 1h 10m | 1h 40m |
| Relaxed 4 km/h, 12 min per 100 m up | 1h 25m | 2h 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 07:05, sunset 16:53. Start by 14:13 to be down before dark, allowing 1h 40m for the walk and an hour for stops.
- Tomorrow: sunrise 07:07, sunset 16:51. Start by 14:11 to be down before dark, allowing 1h 40m for the walk and an hour for stops.
Y Garn summit weather for this route
There is no recent summit forecast cached for Y Garn right now. The main Y Garn page loads the live forecast when you open it. Open the live Y Garn forecast.
Before you go, also check: MWIS Snowdonia forecast · Met Office mountain forecast.
About Y Garn
Y Garn is a 629 m Hewitt, Nuttall and Marilyn east of the Rhinogydd in southern Snowdonia, a quiet summit above the Mawddach valley. More about Y Garn, with the live forecast.
On the lists: Hewitt, Nuttall, Marilyn.
Other routes up Y Garn
| Route | Distance | Ascent | Time up | Grade |
|---|---|---|---|---|
| Ganllwyd and Rhaeadr Ddu forest paths | 4.3 km one way | 600 m | 1h 50m | Hard |
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 690 218, the summit at SH 702 230), 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 eastern ascent: questions and answers
How far is Cwm Mynach eastern ascent?
Cwm Mynach eastern ascent is 2.8 km one way to the summit of Y Garn, with 340 m of ascent. There and back by the same way is about 5.6 km.
How long does Cwm Mynach eastern ascent take?
About 1h 10m to the summit of Y Garn and 1h 40m 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 2h 5m for the round trip.
How steep is Cwm Mynach eastern ascent?
The steepest 500 m averages about 18%, starting 1.1 km from the start, and 11% of the way is steeper than 1 in 5. Cwm Mynach eastern ascent climbs 317 m in all on the track.
Where do you park for Cwm Mynach eastern ascent?
Cwm Mynach eastern ascent starts from Cwm Mynach public forest path. The grid reference is SH 690 218. No checked car park for this start; find lawful parking nearby
Is Cwm Mynach eastern ascent 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 Cwm Mynach eastern ascent today?
By 14:13 at the latest. Sunset on Y Garn today is 16:53, Cwm Mynach eastern ascent takes about 1h 40m 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 Mynach eastern ascent?
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.