Marathon Eryri
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Oct 18, 2026
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One of the most challenging marathons in the UK, featuring five significant climbs through the heart of Snowdonia National Park. The route traverses slate mining towns, remote valleys, and stunning mountain scenery, with the highest point near Pen-y-Pass offering panoramic views of Snowdon and surrounding peaks.
Cool, wet Welsh weather is typical with frequent rain showers and strong winds expected. Runners should prepare for changeable conditions and muddy sections.
Llanberis
The Snowdonia Marathon was founded in 1982, during the golden age of mass-participation running. Now 44 years old, it has established itself as a beloved fixture in Llanberis, growing from its early editions into a race with genuine character and loyal following.
With 1850m of elevation gain, the Snowdonia Marathon is not a course for the faint-hearted. The climbs are where races are won and lost — where the gap between training and undertrained reveals itself without mercy. Locals say the course doesn't beat you; it just waits for you to beat yourself.
The Snowdonia Marathon carries an "extreme" difficulty rating for good reason. The combination of terrain, conditions, and distance creates an event where finishing is a genuine achievement. Drop-out rates are high, preparation requirements are serious, and the line between adventure and misadventure is thin.
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