Marathon Eryri
Mountain road marathon in North Wales
The Marathon Eryri is widely considered one of the toughest road marathons in the UK, with over 1,600m of elevation gain across mountain roads. It develops hill strength, descending economy, and the pacing discipline required for mountain terrain - essential skills for athletes stepping up to trail ultras.
- Total distance: 42.2 km
- Location: Llanberis
- Race Date: 24 Oct 2026
- Finish rate: 100%
- Navigation: Fully Waymarked
- Nearest Station: Llanberis (SMR) (0.9 km)
- Aid Stations: 5
- Night Running: 0% in darkness
- Pacing Complexity: Moderate (39/100)
Marathon Eryri
Mountain road marathon in North Wales
- Distance
- 42.2 km
- Total ascent
- 843 m
- Cut-off
- 9h 30m
- Town/Village
- Llanberis
- Date
- 24 October 2026
The Marathon Eryri is widely considered one of the toughest road marathons in the UK, with over 1,600m of elevation gain across mountain roads. It develops hill strength, descending economy, and the pacing discipline required for mountain terrain - essential skills for athletes stepping up to trail ultras.
Overview
No overview text has been written for this race yet.
Quick Facts
- Entrance Cost: Unknown
- Organiser: Unknown
- Start Town: Llanberis
- Dogs Allowed: Unknown
- Start Date: 24 Oct 2026
- End Date: 24 Oct 2026
- Start Time: 8:30 AM
- Final Cut-off: 9h 30m
Navigation
- Type: Fully Waymarked
- Closest Train Station: Llanberis (SMR)
- Distance from Start Line: 0.9 km
Eligibility
- Minimum Age: 18 years
- Gender Eligibility: All genders
- Minimum Entry Criteria: Unknown
Toilets
- Hand Washing Beyond Sanitiser: Unknown
- Period Products Provided: Unknown
- Female Only Toilets: Unknown
Family & Spectators
- Baby Changing at Start: Unknown
- Family Friendly Spectator Areas: Unknown
- Flexible Deferral or Cancellation: Unknown
Safety
- Marshalls at Isolated Areas: Unknown
- Safeguarding and Reporting Policy: Unknown
- Can Hide Location from Public Tracking: Unknown
Terrain & Elevation
The course covers a genuine mix of surfaces, with paved road (44%) and grass (33%) being the most common and neither clearly dominating. The terrain is highly fragmented, switching roughly every kilometre. This demands constant mental engagement and limits the ability to build a sustained rhythm from surface consistency alone. Climbs are mostly on paved road, though the surface varies across the ascents. Downhills are spread across a mix of surfaces, with gravel most common.
Marathon Eryri has 18.4 km of paved road, this is in the top 25% of all our races.
- Paved Road44% · 18.4 km
- Grass33% · 13.7 km
- Gravel / Track19% · 7.8 km
- Trail / Path3% · 1.2 km
- Rocky1% · 0.3 km
Distance
42.1 km
Ascent
843 m
Descent
858 m
High Point
373 m
Compared against 27 other races of a similar distance, Marathon Eryri has more total elevation gain than 26% of them, and more elevation gain per kilometre than 30% of them — flatter than most races of this distance.
Source: GPX Data
Gradient
4.26%
Average climb gradient
Do you have experience of gentle climbs like Marathon Eryri's, which average 4.26%?
Marathon Eryri's climbs average 4.26%. If your training never rehearses sustained climbing at that gradient, race day will be the first time your legs meet it.
3.7%
Average descent gradient
Do you have experience of gentle descents like Marathon Eryri's, which average 3.7%?
Marathon Eryri's descents average 3.7%. If your training never rehearses sustained descending at that gradient, the downhills will empty your quads long before the finish.
Source: GPX Data
Climate
Pacing Complexity
Marathon Eryri scores 39/100 for pacing complexity, rated moderate.
Similar-distance races score a median of 20/100 (5 races compared).
Marathon Eryri is among the more pacing-complex races at this distance. The challenge is not just the total distance or ascent — it is the repeated need to change effort level. A fixed pace target is unlikely to work here. The dominant source of complexity is terrain type changes, which means preparation should include training runs that deliberately mix different intensities in sequence.
Source: GPX Data
Aid Stations
Stations
You'll need to keep an average pace of between 3.3 km/h and 6.5 km/h between aid stations to make the cut offs.
Stations
| KM | Name | Gap from Prev | Cut-off | Water | Cold Food | Hot Food | Hot Drinks | Gels | Medic | WC | Bags | Crew |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 3.2 | 3.2 km | – | ✓ | – | – | – | ✓ | – | – | – | – | |
| 9.7 | 6.4 km | – | ✓ | – | – | – | ✓ | – | – | – | – | |
| 17.7 | Beddgelert | 8.0 km | – | ✓ | ✓ | – | – | ✓ | – | – | – | – |
| 24.1 | 6.4 km | – | ✓ | – | – | – | ✓ | – | – | – | – | |
| 30.6 | Pen y Pass | 6.4 km | – | ✓ | ✓ | – | – | ✓ | – | – | – | – |
None of the aid stations on this course are confirmed to offer vegan food, so vegan runners should plan to carry their own nutrition.
Source: Not recorded
Are you ready for Marathon Eryri?
Compare it to a race you've already run, or connect Strava and see the three biggest gaps between your training and what this course will ask of you.
