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Across the Rhinogydd – Rhinog Fawr and Llyn Du.

By Dave Roberts   

on May 29, 2011    No ratings yet.

Across the Rhinogydd – Rhinog Fawr and Llyn Du.

Route Essentials

Route Summary

Walk across the Rhinogydd from Bronaber to the sea.

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


22.53 km


671 m


8 hours

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

Start Location


Strenuous Walk


The route can be difficult to follow in places, with some steep ground requiring care and some tricky navigation.

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. 

Across the Rhinogydd – Rhinog Fawr and Llyn Du. Ordnance Survey Map and GPX File Download

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Across the Rhinogydd – Rhinog Fawr and Llyn Du.

Anyone who’s heard of these will know how wild and rugged they are. If you haven’t, then you need to realise that they’re a range of hills that stretch from the Vale of Ffestiniog in the north, to the Mawddach in the south without being breached once by a road. There are two rough and ancient passes that cross these hills, neither of which is more than a path. They are also boggy and rocky in places, and you’d struggle to take anything more than boots on them.

Stray off the paths and you’re in serious terrain. Where there’s no boulders there’s heather, where there’s no heather there’s bogs; usually a malicious mixture of all three. I’ve mentioned before that the Rhinog Kilometer is worth two elsewhere, if not three. Couple that with strangely dipping strata and stone pavements typical of the Rhinogydd, and you’re in a region of mountain that is completely distinctive and unique. You could be dropped off in the middle of them, and while you’d be lost, you’d have no doubt that you were in the middle of the wildest, baddest, meanest terrain Snowdonia can throw at you. Add hill fog and you’ve got a real interesting day.

Distance, Ascent and Time 22.5km, 720m ascent, 8 hours

OS Map Required Explorer 018Landranger 124BMC Snowdonia South

The Route

I’d decided that they were just hills after all, and plotted a route over the whole range from Bwlch Tyddaid south. Nice and easy distance, with just the right amount of ascent. It would be challenging, but not impossible. Well, the first problem was the time of year. It would get dark at half four, and with the manky cloud cover, quite quickly. So every minute was precious. When i lost a full hour due to the bus driver’s wrong instructions, it left me with 5 hours daylight to walk in. So it looked like Llyn Hywel wouldn’t be reached today and instead Llyn Du beneath Rhinog Fawr was decided upon as my target.Across the Rhinogydd - Rhinog Fawr and Llyn Du.

I got off the bus at Bronaber on the A470, and walked a km south on this north-south transport artery before turning right along the minor road that crosses Pont Y Grible. This road takes you easily, never steep, towards the hidden forestry plantations in the valley of Nant y Graig Ddu. The track enters forestry land, but has been recently felled so it looks an eyesore. The path is also boggy, and between some really decent bits has what can only be called shallow pools with logs floating in them. Really strange, like the false quicksand they used to have in black and white cowboy films. I’d advise taking the proper forestry track past the farm house of Graigddu Isaf, as that avoids this hassle.

Across the Rhinogydd - Rhinog Fawr and Llyn Du.

Continuing on the track, it soon forks right into the forest. There is a sign here, one pointing towards Bwlch Drws Ardudwy, and the one we want for the Roman Steps. Don’t relax though, as it’s the last bit of help you’re going to get. The first section of path is exceptionally easy. It’s been surfaced with large gravel that’s been tamped down in a marked contrast to the first bit of path to the farmhouse. It continues like this for enough time to make you complacent, where it then turns into knee deep mud for small sections. Care will get you past them, but I tend to avoid falling into bogs and suchlike when my walking companions are walking with squelchy boots. Yes, I may be slow, but I keeps me feet dry.

Across the Rhinogydd - Rhinog Fawr and Llyn Du.

Navigation though, you’ll be glad to know, is quite straightforward. The path tends to follow the stream, and keeps plodding very gently uphill. You’ll pass the waterfall of Pistyll Gwyn that falls over a short, angular drop typical of the area. There wasn’t much water flowing over it today, which made the bogginess of the route even more surprising. Past the waterfall, and through the trees you are not long until you reach open hillside and get a close up glimpse of Rhinog Fawr. Today I saw heathery slopes disappear into the mist. At least the path was clear, and the route up to Bwlch Tyddiad was quick from here. There are a number of paths that lead up to Llyn Du along here, and they are probably easier than the route I took, but I only realised they were below the bwlch once I’d reached it. So I plodded down the other side of the bwlch, along a pavement of rock until a wall is reached.

Across the Rhinogydd - Rhinog Fawr and Llyn Du.

This wall is the key to navigation as it can be followed now all the way to Llyn Du. Some sections are quite steep, and being damp rock made the going very slow. But you’re making steady progress and it’s easier than heading cross-country across this sort of terrain. Rhinog Fawr is quite similarly featured all around. It’s comprised of layers, which are flat, with sheer drops in between. So you keep completing steep sections, then a flat one, before moving on to the next layer. You’ll pass a couple of strangely dipping strata too, which made me a bit dizzy if I looked too long.

Llyn Du is clearly visible from the wall, even on such a misty day as this. You can see even more dipping strata at the far end of the lake, where you’d slide helplessly into the dark waters. I camped at the wall end, right near the lake. It was the driest spot and was clear of heather. I decided that an hour and a half of daylight wasn’t long enough to go for the summit, especially as there wasn’t a clear path and the mist was so thick.

After a reasonably calm night, i awoke to find the mist had fallen and wasn’t shifting. So I rounded the lake to reach the outfall river and climb the mountain that way. Not the easiest start to the day, as the path soon vanishes and you’re desperately scrambling over boulders on the lakeside. A faint path leads right, up the hill. One also continues onwards and is the path up i missed up yesterday. While the path is reasonably obvious for most of the way, it’s also steep and often loose. In these conditions, it was slippery and care was needed. It’s definitely a scramble, and for the first time i could appreciate the design of my OMM Villain pack that’s meant to excel for climbing and scrambling. I didn’t feel it was in my way at any point.

Across the Rhinogydd - Rhinog Fawr and Llyn Du.

A ledge is reached before long, and a couple of other paths converge here. One seems to have come up parallel to you, but you can’t see where. Another comes up from a much easier path up that followed the wall that was abandoned this morning. Hindsight is a marvellous thing. The path up is another sharp bend in the path, and takes you directly up along some more steep scrambling but directly to the summit. There is no doubt an easier path further along, but in the pea souper today, I was glad to just reach the summit.

There is meant to be an unrivalled view from the summit. I’ve no doubt of that, but saw nothing on a day like this. I had been hoping, rather optimistically, that I’d emerge into a blue sky with the summits floating in the sea of a temperature inversion. There is a trig point, collapsed cairn and a shelter on top at least, and I found that the bearing I took to get off the summit took me directly from the trig to the collapsed cairn. Now the rest was just guesswork. I could follow a bearing, but as there was no real path on the map beyond the summit, there was little point. The terrain is so dynamic, that any path you take is tortuous and gut feeling is more useful than pure navigation. So a rough bearing East to start with, followed by a veering off south was all I had to go on. fortunately, there was a path that followed most of this. It disappears by a section of rock pavement, but there are cairns at that point. I left the pavement to follow cairns that took me away from the rock, but then lost my conviction and contoured around the hill to find myself at the edge of the pavement, looking down over a seeming precipice. I should have followed the first path, and had visibility been better, no doubt I could have seen that it took me down the slope to the path beyond Bwlch Drws Ardudwy, or to another precipice, who can tell.

Across the Rhinogydd - Rhinog Fawr and Llyn Du.

Fortunately, I heard my first human company of the trip at this point (I’d smelt a large herd of goats just before this). They were below the precipice, and climbing up to the point at which I was stood. Looking behind me revealed a line of cairns vanishing into the mist, so was one of the main routes up. The men arrived at my location, there was no point in me descending until they were out of the way – it was far too treacherous. They asked how far they had to go, and the general going. I said that what they’d just come up was the worst bit I’d seen and was there an easier way I asked, again overflowing with misplaced optimism. No, and the boulderfield below the cliff was an even worse obstacle. I wished them luck, they did likewise; we certainly needed it.

Slowly, deliberately, with my feet, hands and buttocks desperately gripping any available holds, I made it to the boulder field. This was painful. You can see the path, but you know you’ve got to cross all the boulders to get there. So arse scrambling technique at it’s very best was employed to cross them; resulting in yet another pair of Fueras with a torn seat. I don’t have the face to take yet another pair to my local dry cleaners and ask them to sew them up.

I nearly kissed the path once I was onto it. I even thought I’d shred my platypus bladder as my trousers were getting wet, but fortunately it was just a loose cap. The trip from Llyn Du to Bwlch Drws Ardudwy was a mere 3km and 200m ascent, but had taken over 4 hours. I’d stopped for a short breather on the ascent, and maybe 30mins on the top, but it was still a good example of how this sort of terrain can hamper your progress to a crawl. Had I started for the summit last night, I’d have been forced to rough it out for an uncomfortable night on the mountain.

With all the lost time, a descent to the sea at Llanbedr was the most attractive option. I could have returned along the path to Bronaber, but buses were infrequent and I wasn’t sure exactly where the pub was. I knew there were trains from Llanbedr and that I’d find shops and pubs, so waiting for any transport wouldn’t be at all unpleasant.

I’d expected an easy path down from the bwlch. It is in places, but is also very rocky and slippery in the places where it wasn’t boggy and slippery. Further down there are large slabs making the bogs easy to cross, but it’s still a relief to reach the minor road when you’re trying to get to the end of the walk in an unreasonably short time. Cwm Nantcol would, I’m sure be much more interesting if I’d taken my time and if the mist hadn’t obscured all the higher slopes. There are also footpaths that could be taken in place of the road, but I had a train to catch – which I missed by a matter of minutes. There’d be a bus along soon to take me back along the Rhinogydd, but walking is the only way across.

Local Information and Recommended Maps and Guidebooks

Route Summary:

Walk across the Rhinogydd from Bronaber to the sea.

This walk includes the Washi of Rhinog Fawr

This walk includes the Hewitt of Rhinog Fawr

This walk includes the Nuttall of Rhinog Fawr

Route Start Location:

22.53 km 671 m 8 hours

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

Activivity Type: Strenuous Walk

Summits and Places on this Route


none noted


The route can be difficult to follow in places, with some steep ground requiring care and some tricky navigation.

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 :

Public Transport:

Traveline for UK Public Transport

Recommended Maps


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Dave Roberts

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3 thoughts on “Across the Rhinogydd – Rhinog Fawr and Llyn Du.”

  1. Da iawn Dave Roberts. Stumbled across this whilst thinking about a trip to the Rhinog area to practice navigation skills with a friend who’s studying for her ML course…

  2. Croeso! If she can nav there, she’ll be sorted… I’d imagine one of the toughest assessments would be night nav in the Rhinogyddd – brings me out in a cold sweat just thinking about it!

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