RunThrough Trails Snowdonia Sea2Sky
From the beach at Barmouth into the Eryri mountains.
| Distance | Ascent | Per km |
|---|---|---|
| 53K | 1,647 m | 31 m |
| 25K | 739 m | 30 m |
| 12K | 600 m | 50 m |
Nobody has reviewed this one yet
No reviews of the Snowdonia Sea2Sky, and nothing on what people wore. Both are things no organiser publishes and every runner wants before they enter — how it actually went, and what was on your feet.
Ran it? Write the first reviewRunning it soon? Connect Strava and we will ask you about it the day you finish, so you do not have to remember to come back.
Pick your distance
11h cut-off, which needs 12:27/km
6 checkpoints
What you’re in for
Barmouth beach to the summit of Cadair Idris and back down again — sea to sky and home. Three distances from an eleven o'clock start: a 53K with 1,647m of climb and eleven hours, a 25K with 739m, and a 12K with 600m and four hours, which has no aid station on the course at all. Up through the old oak woodland, out across open ridge, and back down to the coast with the Mawddach estuary below. Early September. Cupless aid, and the kit list includes a taped-seam waterproof with a hood even on the 12K. Coast at both ends and a proper mountain in the middle, which is a rarer shape of race than it sounds.
Terrain and trail
Promenade and lane out of Barmouth, rooty single-track through the oak woods, then open mountain — grass, rock and scree on Cadair Idris, with the summit exposed to whatever the Irish Sea sends — and the estuary paths back. Marked. A trail shoe with grip.
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Aid stations
Six aid stations on the 53K.
Cut-offs
Eleven hours on the 53K.
Train for it: routes near the start
Routes starting within 20 km of Barmouth, Gwynedd, nearest first. Each one has a free GPX file and a TRP grade, so you can rehearse the ground before race day.
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Other races near here
Eryri (Snowdonia) races →Races from other organisers starting within 30 km of Barmouth, Gwynedd, nearest first.
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How to enter
No date announced for the next running yet. RunThrough Trails’s site ↗ is where it will show up first.
Common questions
- The Snowdonia Sea2Sky offers 3 distances: 53K (32.9 miles), 25K (15.5 miles), 12K (7.5 miles).