Dexter Gully: Route Description and More
By The Bald Scrambler
Dexter Gully
Published By: Daniel Woodley. Updated: 17th October 2023. 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.
An alternative to the popular Sinister Gully and an exciting prelude to greater adventures on Bristly Ridge, scramblers often ignore this route for its neighbour but is it time to add Dexter Gully onto the “must do” list?
I first scrambled up this gully over a decade ago, and at the top, I found lots of sludge, grass, moss and plenty of shattered rock – more than enough to make getting a handhold difficult.
I also vividly recall telling myself that I would never do that route again!
Fast-forward ten years, and I’m back; this time I found the gully much easier. Perhaps that’s due to experience, conditions on the day or because much of the loose rock and grass at the gully top are gone. Either way, it just seemed only slightly more challenging than Sinister Gully next door.
Welcome to The Bald Scrambler and my route description of Dexter Gully.
Approach
I always scramble up Tryfan’s North Ridge and then descend via the south ridge to the pass (Bwlch Tryfan) before heading up one of the gullies and onto Bristly Ridge – this just makes more of a day of it, but there is a more direct route:
If possible, park in one of the free laybys on the A5 just east of Ogwen Cottage.
Take the path left of the toilet block near Ogwen Cottage up the wide steps and after a short distance, take the left fork and follow over a footbridge. After 200 metres or so, the path will curve rightwards, take a slightly narrower path to the left, ascend a steep path next to and then over a stream up to the left bank of Llyn Bochlwyd.
Continue to the pass where you’ll see a stone wall in front of you, Tryfan’s south ridge to your left and Bristly Ridge to your right.
Follow the stone wall to the right up to Sinister and Dexter Gullies. I then usually take a well-polished line between the two gullies until I come to the retaining wall (see photo).
Sinister is the left gully, and you’ll need to scramble over the short man-made retaining wall to reach it, while Dexter is to the right.
See photos and video.
Sinister and Dexter Gullies and the stone wall.
A small man-made retaining wall marks the route to Sinister Gully. Ignore and go right to reach the start of Dexter Gully.
Dexter Gully as viewed from next to the small retaining wall. Note the loose stones – a sign of things to come.
Imagery © 2023 Google, Airbus, Bluesky, Infoterra, COWI, Cnes/Airbus, Getmapping PLC, Landset, Maxar Technologies
Ascending Dexter Gully
Dexter Gully contains more loose stones, dirt and vegetation than its neighbour, Sinister Gully. While the situation at the top of the gully has improved, the central section still has areas that require patience and attention.
I found the best line was directly up the centre all the way to the top.
To avoid the loose top section, one can take an easily missed left line from about three-quarters of the way up. This rises above the gully and bypasses the loose section but is difficult to locate, although the line is easier to see once you’ve reached the top and are looking down the gully.
If you want to know which line I took, check out my video, which also contains information about the approach, the retaining wall and the left avoidance line near the top.
Photos From Within Dexter Gully
(click to expand)
Looking up Dexter Gully
Now you know why the loose stones are a hazard on this route! Yes, that is a very steep drop.
Descents and Continuation
I don’t recommend descending Dexter Gully; the loose stones could be an issue.
The quickest way to descend would be to take a line leftwards from the top of Dexter Guly into Sinister Gully and descend from there, but this route would be best if you have previous experience of that gully as there is one steep section to overcome.
Most scramblers continue up onto Bristly Ridge proper and onto Glyder Fach. Dexter Gully isn’t usually scrambled without a continuation.
Comparing Dexter Gully to Sinister Gully – Which Should You Choose?
If you’ve never scrambled up Bristly Ridge before, I suggest going up Sinister Gully, the handholds are more solid, and there’s less sludge and fewer loose stones. The one steep wall in Sinister can also be avoided if you have the know-how.
While both gullies are a grade 1 scramble, Sinister is more enjoyable and is far more popular.
Don’t be put off by the unusual names; sinister is Latin for left or left side while dexter is Latin for right, or right side (source).
For those of you who have already ascended Sinister, check out the photos and videos on this page and decide for yourself if you want to give it a go, I didn’t encounter any issues beyond some loose stones and a few slippery rocks that required some care and patience.
Route Profile and More Info
Scrambling Grade: Grade 1.
Navigation: Literally straightforward once you’re in the gully. The approach could be problematic in poor weather.
Dangers: Loose rock throughout, risk of loose rocks falling from scramblers further up the gully, sludge in the mid and top section, grass and lack of handholds at the very top, slippery rocks when wet, steep drops.
Approach Time: 1hr 15m
Ascent Time: 15-20 mins (exc the Bristly Ridge continuation which is quite an undertaking).
Popularity: Often ascended by mistake by those who confuse it with Sinister Gully.
Fun Rating: 7/10.
My Dislikes: It’s a short gully and over way too soon. The loose stones and the usual slippery rocks found in many gullies.
Kit List: My kit list is here.
Similar Routes in Snowdonia: Idwal Staircase, Sinister Gully, Nor’ Nor’ Groove, Seniors Gully, Y Gully, Main & East Gullies, Milestone Gully.
More:
I really enjoyed Dexter Gully, and I’ll definitely do it again next time I go up Bristly Ridge.
I initially found this route in a guidebook called “Scrambles in Snowdonia” by Steve Ashton. It was first published back in 1980 but has been updated several times since, most recently in 2017.
If you want a guidebook to take with you on scrambles, this compact book is the best.
About Daniel Woodley
This description of Dexter Gully was created by Daniel Woodley, aka The Bald Scrambler.
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 aka The Bald Scrambler
Have fun, keep safe. Hopefully I’ll see you on the mountains one day
By The Bald Scrambler