Marathon de Snowdonia Eryri 2026

Marathon de Snowdonia Eryri is a mountain marathon in the heart of Wales, based around Llanberis and the Snowdonia/Eryri area. It is a full 26.2-mile road race with significant climbing, so the challenge is not just the distance but the sustained ascents that strain the calves and disrupt any steady rhythm. The setting consists of mountains, open countryside, and lakes, with clean upland air and broad views rather than a flat city course designed for easy pacing. The route guides runners through varied Welsh terrain near Snowdonia’s peaks and lakes, suiting those who seek a demanding marathon over a straightforward time trial. After the finish, Llanberis provides the race with a distinct local hub: the National Slate Museum recounts the area’s mining history, the Snowdon Mountain Railway ascends into the surrounding mountains, and Llyn Padarn is situated nearby for a walk or picnic. Caernarfon Castle, a UNESCO World Heritage site, is also in proximity, facilitating a weekend excursion around North Wales.