Snowdonia Marathon

The Snowdonia Marathon, known as Marathon Eryri from 2023, is a marathon in Snowdonia (Eryri), North Wales. It was established in 1982 as an alternative to city and town races. The route makes a circumnavigation of the Snowdon massif, starting and finishing at Llanberis. It is held annually in October.

In a 2007 poll by Runner's World Magazine, the Snowdonia Marathon was voted the best marathon in the UK.

The marathon announced in June 2023 that it would be known as Marathon Eryri in future, citing the removal of the term Snowdonia by the national park authority a few months earlier.

The marathon starts and finishes near the village of Llanberis at the foot of Snowdon. It follows the road through Nant Peris (the former starting point) up towards Pen-y-Gwryd. From there it descends to the shore of Llyn Dinas and continues to the village of Beddgelert. It then loops back on the other side of Snowdon as far as the villages of Rhyd-ddu and Waunfawr before traversing the slopes of the mountain to finish back in Llanberis. Over 2000 runners were registered for the 2010 race.

Media coverage
A television highlights show is produced and aired by S4C. The BBC reports the news and winners on BBC Radio Wales and BBC Radio Cymru.

Half-marathon
Since 2012 there has also been an annual Snowdonia Half Marathon, held in April, and mostly run on roads between Llanrwst, Trefriw and Betws-y-coed.