Tregalan Couloir Scramble

By The Bald Scrambler


Published By: Daniel Woodley. Updated: 3rd May 2024. Filed at: Snowdon 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.

I really enjoyed going up the Tregalan Couloir grade 2 scramble, it was better than I was expecting, given the low rating in my guidebook.

If you’re thinking of trying this route, I suggest going in dry conditions as the runnel is slimy and super slippery after rain. If you go as part of a group, consider a helmet as there’s plenty of loose scree, especially near the top.

Below you’ll find route description, photos, map and video:

Please read my disclaimer before reading further as scrambling is a dangerous sport and there are plenty of wet, slimy, slippery and steep sections on this route!


I walked up the Watkin Path until the final ruin, just before the path steepens, here I came off the Watkin Path and went straight ahead, instead of taking the path rightwards.

This map shows the approximate route to the foot of the Treglalan Couloir scramble:

Download file for GPS

Below is a photo showing the two gullies, you want the one on the right (hidden).

There is a gully to the left, with an obvious overhang. Tregalan Couloir is to the right of this.

Pointing the way to Tregalan Couloir

Ignore the overhung gully to the left, Tregalan Couloir is to the right and is partially hidden from view

Start of the Scramble

At the gully mouth, I took a line to the right, marked by obvious white quartz lines (similar to a spider web).

Without going too far, I then re-entered the gully (tricky downclimb) and ascended the gully bed to a clear fork:

Fork in the gully

The unmissable fork in the gully

Eastern terrace of cloggy scramble - start

Initially I took the left line, into an obvious runnel

Scrambling the runnel section

The runnel is steep in places with dried slime/lichen in the centre

The zigzag path

At the top of the runnel, I took a right (hard to find, not obvious) and traversed into the right gully

The Mid Section

In the midsection of the gully, I found plenty of loose scree and larger boulders and two sections where I had to scramble out of the gully to the left before re-entering the gully.

I found the scrambling intermittent but enjoyable:

Loose scree and boulders in the gully bed

Loose rocks and stones in the gully – the scrambling does improve further up

Scrambling section in Tregalan Couloir

At the two challenging sections, there is an enjoyable (grade 2) scramble out to the left of the gully bed

Loose rock

Watch out for loose holds 🙁

The Upper Section

There’s plenty of scrambling in the upper section of the gully but there’s also much more scree in and around the gully bed. So much so that I recommend a helmet if you have anyone ahead of you.

Loose material in Tregalan Couloir

Lots of loose scree in the upper section

The top of Tregalan Couloir

Nearing the top of Tregalan Couloir

Topping Out

The route ends on the South Ridge route with the summit of Snowdon less than an hours walk away.

South Ridge Route

Taking a breather at the top with Snowdon in the background

My Rating

This route is graded as a 2 on the UKC website, and also in Steve Ashton’s Scrambles in Snowdonia book.

Personally I feel that’s about right although it may feel more intimidating after rain, especially in the runnel.

This is a deceptively long route with varied scrambling from solid rocks to slime, loose scree and a few loose holds as well.

In Ashton’s book, they’ve given it a 1 star fun rating (out of 3) and I would probably rate it slightly higher.


From the South Ridge, either descend back to the Watkin Path or summit Snowdon.

I don’t recommend descending Tregalan Couloir.

Route Profile and Information

Scrambling Grade: Grade 2 in Steve Ashton’s guide.

Suitability for Beginners: In my opinion, it’s not suitable for complete beginners who should gain experience with other lower-grade routes first.

Navigation: The walk-in is long and it’s hard to see the gully until you are very close to it.

Dangers: Moss, lichen, wet slimy rocks, loose rocks. Hard to find the point where one needs to cross over from the runnel to the right gully.

Approach Time: 1hr 15mins.

Height Gain: 250 metres or so.

Popularity: Not very popular at all.

Fun Rating: 6/10.

My Likes: One for the completists, I would do it again if I were in the area but I wouldn’t go out of my way to come here. Some decent sections of scrambling; the runnel was fun.

My Dislikes: Loose friable material in the upper section, a scrappy inconstant scramble.

Nearby Scrambles:

Snowdon Horseshoe (grade 1)


I’ve scrambled up Tregalan Couloir twice now and it’s an unusual and unfrequented route but well worth the detour from the Watkin Path in good weather.

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 Snowdon 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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