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Full Moelwynion and Moel Siabod Traverse – Maentwrog to Capel Curig

By Dave Roberts   

on February 23, 2023    No ratings yet.

Full Moelwynion and Moel Siabod Traverse – Maentwrog to Capel Curig

Route Essentials

Route Summary

See the end of the article for local information about parking, public transport facilities, pubs and cafes.


35 km


2020 m


12 hours plus or 2 days

Calculate the time using Naismith’s Rule and factor in your own pace.

Start Location

Maentwrog to Capel Curig


Epic Walk


Distance, navigation and a few seriously wet bogs to cross.

Weather Forecast:

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Remember that we cannot outline every single hazard on a walk – it’s up to you to be safe and competent. Read up on Mountain Safety , Navigation and what equipment you’ll need. 

Full Moelwynion and Moel Siabod Traverse – Maentwrog to Capel Curig Ordnance Survey Map and GPX File Download

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Full Moelwynion and Moel Siabod Traverse – Maentwrog to Capel Curig

There’s little doubt in my mind that the full traverse of the Moelwynion is one of the most satisfying trips you can take in Eryri (Snowdonia). It compares favourably to similar routes such as the Rhinogydd Traverse and the Carneddau Traverse, and the traverse of the range across from Beddgelert towards the and on to Dolwyddelan.

The walk starts off at sea level near the Oakley Arms taking you past the scenic wooded Llyn Mair before taking you onto the mountain environment proper. From there on, it’s hard work, but when you arrive in Capel Curig the next day, or even at sundown on the same down, you’ll have completed one of the more satisfying traverses in the park.

Full Moelwynion and Moel Siabod Traverse – Maentwrog to Capel Curig Route Description

1 Follow the B4410  road from the Oakley Arms towards Llyn Mair, this section is around 0.5km.

2 Leave the road left to join the footpath around Llyn Mair. This is a good path, and pleasant walking that contrasts with the rugged wild walk that’s ahead. 

3 After 1.2km you’ll end up at a picnic area. It’s probably too soon for a break, so head across the road to follow the good path through the woodland and on towards Tan-y-bwlch railway station.

4 At Tan-y-bwlch, cross the bridge over the railway and a good path leads you to join the minor road for Croesor.

5 Follow the minor road ahead and follow this road for 2.7km. There’s a conifer plantation to your right for most of the way, but as soon as this gives way to open hillside you need to keep an eye out for another small plantation and the right of way you’ll need is just inside this to your right.  The plantation is currently looking rathe sorry for itself, and has a few straggly trees left.

6 Follow the track right through the plantation and it soon leaves it for open hillside. The path is faint and rather wet initially, but the going improves as you climb the grassy ridge all the way to the summit of Moelwyn Bach. Now you’ve earned a break, and you’ll be glad to know that the views from here are quite extensive.

7 From the summit there’s a hard to find path to the NE, which is easy enough to follow as it drops down towards Bwlch Stwlan and gets clearer as it goes. There are pleasant views towards Llyn Stwlan, which is the upper lake for the pump storage Ffestiniog Power Station, and towards our next mountain, Moelwyn Mawr.

8 The path pulls up from Bwlch Stwlan up over Craigysgafn and may need the use of hands on a couple of steeper sections at the start. The going then becomes steady over the minor summit of Craigysgafn before a final grassy slog up to the summit of Moelwyn Mawr. This section follows the line of the Cambrian Way.

9 – You can, optionally, pick off the outlying summit of Moel-yr-hydd before heading to Rhosydd Quarry. The direct route follows the Cambrian Way down the grassy north ridge over the minor Moelwyn Mawr North Ridge Top, while a longer option is to keep right along the head of the cwm and follow a faint path towards Moel-yr-hydd. The path is barely more than flattened grass, but straightforward enough in fine weather.  Be warned that in between these two lines lie two huge quarries – that can be quite hidden from view. 

10 – From Moel-yr-hydd  you’ll need to head on a rough bearing to Rhosydd Quarry, roughly ENE, but take a bearing if in mist from the map to follow. Here, you’ll re-join the line of the Cambrian Way as far as Cnicht. The route heads downhill, to Bwlch y Rhosydd and there’s plenty of industrial archaeology that can be explored with care.  It’s probably a good idea for those taking two days for the walk, to ensure plenty of time along the way to spend at these points of interest. Those passing through in one day will need to get moving.

Rhosydd Quarry was opened in the 1830s and while it was operational sporadically until 1947, including being owned by the Colemans of mustard fame, was never that successful. This was largely down to the remote location of the quarry, something you can appreciate while you sip your coffee among the ruins and chomp your kit-kat.

11 – From Bwlch y Rhosydd you can almost pick your way across towards Ysgafell Wen. The most obvious is to continue along the route of the Cambrian Way towards Llyn Cwm Corsiog and Llyn yr Adar, which can still be tricky to follow in places. You can easily spend hours exploring all the little tarns along the way

12 – The path eventually climbs to reach the grassy ridge between Cnicht and Ysgafell Wen where you can turn left and take a dog-leg to Cnicht, one of the highlights of this walk. The path is reasonable clear and is a 4km round trip with only 100m of ascent, and the summit of  Cnicht marks the half way point on this epic traverse, though you’ve completed around two thirds of the ascent. Don’t get complacent, as the next section between Ysgafell Wen and the climb up Moel Siabod is rough going. At least by splitting the trip up, you’ll be fresh for the challenge in the morning.

13 – Having returned to the point 12 above, a faint path of sorts can be followed towards the complex terrain of Ysgafell Wen. It’s up to you whether you want to head for the main summit, or make a beeline to hit the broad ridge instead as there’s a number of options. Once on the ridge, you can follow the fence line – basically as far as Moel Siabod! In mist, very good navigation is a must, and even in fine weather you’ll need to check the map frequently. Once at the broad ridge, follow the fence line left, you should be able to see the broad ridge as far as Moel Siabod.

14 – I stopped around Llynnau’r Cwn for the night, as good a spot as any!

The evening was fine and pleasant, but unfortunately the weather the next day meant I had to pack the camera in a drybag and I’ve used images from other trips to illustrate the next half of the walk.

15 The going gets really wet and rough as you approach Llyn Edno, with wet boots a possibility. Not to be negative, but this section is nothing compared to the next section. It’s a sizeable lake and a most beautiful spot to stop if you have the time.

16 You’ll encounter some seriously boggy bits as you leave Llyn Edno on the section to Bwlch y Rhediad. You can avoid the worst by taking advantage of any stiles, but there’s a section once in final view of the safety of Bwlch y Rhediad that requires quite a leap of faith!! Anyone making it through this section with dry boots is doing well for themselves, and even not losing a boot or sock to the bog should be seen as quite the accomplishment.

This section is rough, very rough. The paths are narrow and heathery, and when they are not they are bog. Thankfully, the path is reasonably easy to follow as it keeps to the fence, so it has that going for it. Seriously, allow plenty of time to get from Llyn Edno to Bwlch y Rhediad, as I’ve found the going to be slow each time I’ve crossed it. I think of this section a bit like Eryri’s answer to the Darien Gap…

17 Finally at Bwlch y Rhediad, you can relax a little. There’s some boggy sections to come, but it’s not as bad as the previous section. You’re now a bog ninja, fully trained in the art of avoiding and bypassing these obstacles. Either that, or you’re still stuck somewhere in Eryri’s Darien Gap. Continue following the fence line, and after a short climb and a few more wet sections (which the OS have suddenly decided to mark on the map) you’ll be at the summit of Carnedd y Cribau. This minor hill has a small tarn on the summit and stupendous views towards Yr Wyddfa (Snowdon)

18 From Carnedd y Cribau the going eases a little, and while being pathless is much easier than the previous section. Keep an eye out for the twin lakes of Llynnau Diwaunydd to your right, and of course the dominating view towards Yr Wyddfa remain breath-taking. The route continues over the knoll of Clogwyn Bwlch-y-maen before embarking on the final ascent on the walk. Up the grassy ridge to Moel Siabod, still following that dogged fence line along a distinct grassy path.

19 You’ve finally make is to Moel Siabod’s summit and the highest point on the walk at 872m high. You’ll arrive with the day walkers, who have taken the short way up, or if completing it in a day you’ll hopefully be treated to a spectacular sunset over Yr Wyddfa as you finish the walk.

20 Finally, the descent from Moel Siabod  to Capel Curig. If you’ve made it this far, you’ll need little instruction on how to follow the path down. Other than being rather sketchy from the summit, you’ll need a bearing in mist, once you’re on the track the going is good all the way down to Plas y Brenin in Capel Curig.

Local Information and Recommended Maps and Guidebooks

Route Summary:

This walk includes the 6 Washis of Moel Siabod, Moelwyn Mawr, Moelwyn Bach, Cnicht, Ysgafell Wen, Moel Meirch

This walk includes the 6 Hewitts of Ysgafell Wen, Ysgafell Wen North Top, Moel Siabod, Moelwyn Mawr, Moelwyn Bach, Cnicht

This walk includes the 9 Nuttalls of Ysgafell Wen Far North Top, Moel Siabod, Moelwyn Mawr, Moelwyn Bach, Cnicht, Ysgafell Wen, Ysgafell Wen North Top, Craigysgafn, Cnicht North Top

Route Start Location: Maentwrog to Capel Curig

35 km 2020 m 12 hours plus or 2 days

Calculate the time using Naismith’s Rule and factor in your own pace.

Activivity Type: Epic Walk

Summits and Places on this Route


There’s a pub at the start of the walk at the Oakley Arms, and a choice in Capel Curig including the café bar at Plas y Brenin. There are also toilets at the start and a posh paid for portaloo at the parking at Capel Curig.


Distance, navigation and a few seriously wet bogs to cross.

Remember that we cannot outline every single hazard on a walk – it’s up to you to be safe and competent. Read up on Mountain Safety , Navigation and what equipment you’ll need.

Parking :

Not really an option or recommended at the route start.

Public Transport:

Plenty of buses to the start and end point, but not straightforward to return to start. You can base yourself in Caernarfon or Porthmadog that have reasonable services to both the start and end of the walk, though you may need a change of bus and you will need to plan well ahead.

Traveline for UK Public Transport

Recommended Maps


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Dave Roberts

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