Atlantic Slab/Ridge Scramble in Snowdonia

By The Bald Scrambler

Atlantic Slab

Published By: Daniel Woodley. Updated: 23rd June 2024. Filed at: Glyderau Scrambles. Disclosure: I may earn a commission from purchases made via links. Disclaimer: Scrambling is a dangerous sport, this route description does not provide step-by-step instructions. Read Disclaimer.

Atlantic Slab, also known as “The Ridge” or “Atlantic Ridge” is a 300-400m long upturned slab of rock that used to form the ocean bed. The slab has a distinctive wave pattern on its surface and there’s an abundance of fossils to be found as well.

There are several routes here, with the right edge of the slab being of interest to scramblers.

This scramble is graded as a 2+ in the most recent edition of Scrambles in Snowdonia but on various climbing and scrambling sites, it’s often rated as a 3 or a “Mod” climbing grade.

Here you’ll find:

  • Parking info
  • Approach
  • Route description
  • Continuation
  • Photos and video

Watch the video:

Please read my disclaimer as scrambling is a dangerous sport and there are many dangers on this route!

Parking For Atlantic Slab

I drove down the single track road behind the Ogwen Cottage/Visitor Centre through Nant Ffrancon and found a layby spot a hundred metres or so before the Snowdonia Mountain Hostel.

There’s limited parking on this road as most of the laybys are also marked as passing places, but there are a few other spots on the road that could be used for parking.


I went over the steps next to the hostel and across ground that was initially boggy (15 metres or so) and then followed the drystone wall for about 45 minutes until an obvious diagonal line of boulders and scree which led away from the wall to the toe of Atlantic Slab, which is the leftmost slab on the cliff.

Overall the approach took about an hour but felt like more.

Approach to Atlantic Slab

Photo shows the hostel in the background and the drystone wall

Route to Atlantic Ridge

The diagonal line of boulders/scree from the wall leading to Atlantic Slab

Atlantic Slab/Ridge Map

The route I took

Scrambling Atlantic Slab/Ridge

The lower half of the slab is slightly steeper than the upper half and nowhere near as steep as other grade 3 routes I’ve tackled such as Cneifion Arete and Dolmen Ridge but there’s nothing to break the fall should one slip so it did feel intimidating, even more so as I gained height.

I started at the toe and took a line to the right of the slab and never went more than 5 metres from this edge.

Occasionally I would move slightly to the left and a couple of times I stepped down to the right before regaining the right edge of the slab again.

Atlantic Slab isn’t one huge smooth rockface but is broken up by grooves, runnels and narrow ledges, many of which are filled with heather and some small amounts of grass.

The rock was super grippy and there were plenty of holds and lines to choose from.

Typical scrambling on the lower section of Atlantic Slab/Ridge

Typical scrambling on the lower section of Atlantic Slab/Ridge

The Second Half of the Scramble

Atlantic Slab isn’t straight but is curved with the upper half slightly shallower, this means that above the halfway point, I couldn’t see the ground and I could see why some people online have described this route as committing.

I found the upper half of the route slightly easier but there were a few more loose holds and some lichen near the top which wasn’t an issue due to the dry weather.

Upper section of Atlantic Slab

The top of the scramble

Topping Out

I stayed true to the right edge of the Atlantic Slab all the way to the top but I read online that some climbers venture out to the left near the top to maintain the exposure. I would only suggest this if the rock is dry due to lichen on the final 50m or so.

Looking down Atlantic Slab/Ridge

Looking down Atlantic Slab/Ridge


I took the most direct route back to my car which was south over the wall via the steps and then east down the other side of the cwm (faint path, grassy) and then circled back to the drystone wall I had walked next to on the way up:

Descent from Atlantic Slab

Map showing the descent route I took (grassy, could be slippery in climbing shoes)

There are several scrambling routes south of Atlantic Slab that are within reasonable walking distance; Needles Eye Arete, South Arete and even Yr Esgair, if you’re feeling suicidal.

Route Profile and Information

Scrambling Grade: Grade 2+ in Steve Ashton’s guide, but I rate it a low 3.

Suitability for Beginners: No.

Navigation: I found it easy, I just followed the drystone wall to the diagonal line of scree/boulders.

Dangers: Very little to break one’s fall in the event of a slip. A few loose holds and some lichen, mostly on the upper section.

Time: Allow 2.5 hours to the summit, inc the approach, longer for roped parties or slow scramblers.

Length/Height Gain: 200m height gain with a total length of somewhere between 300 and 400 metres.

Popularity: This is the quiet side of Ogwen and I was alone on the ridge.

Fun Rating: 8/10.

My Likes: A quiet, long route with bucket loads of exposure.

My Dislikes: Too much vegetation, long walk in.

Nearby Routes in Snowdonia: Needle’s Eye Arete, South Arete, Yr Esgair.


This is one of my favourite routes on this side of Ogwen Valley and is well worth the effort in my opinion.

This scramble is also included in Steve Ashton’s “Scrambles in Snowdonia”, which is a bible of sorts for scramblers.

If you’re new to scrambling or want to find new routes, try this compact book that is small enough to fit in your backpack and maybe even your pocket.

Recommended Guide Book:

Scrambles in Snowdonia

Scrambles in Snowdonia by Steve Ashton (#ad)

About Daniel Woodley

These photos and route descriptions were created by Daniel Woodley, aka The Bald Scrambler and this page forms part of the Glyderau Range Scrambles.

From walking along beaches and kayaking down rivers to making his way up mountains and even jumping out of planes, Daniel has a love of the outdoors but scrambling is his real passion.


Daniel Woodley

Daniel Woodley aka The Bald Scrambler

Have fun, keep safe. Hopefully I’ll see you on the mountains one day

By The Bald Scrambler

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