Marathon Eryri, formerly known as the Snowdonia Marathon, is one of the United Kingdomβs most celebrated and challenging road marathons. Held in Llanberis, Wales, United Kingdom, the race takes runners on a spectacular 26.2-mile journey around Yr Wyddfa (Snowdon), the highest mountain in Wales. Combining major climbs, fast descents, exposed mountain scenery and notoriously unpredictable late-October Welsh weather, Marathon Eryri offers a dramatically different experience from the flat, fast courses associated with most major city marathons. The event itself describes the race as the UKβs toughest marathon, and its demanding course has earned it a distinctive place on the British running calendar.
The race dates back to 1982, when local runner Ken Jones conceived the original Snowdonia Marathon following the success of the inaugural London Marathon. Jones worked with London Marathon co-founders John Disley and Chris Brasher to establish a marathon that showcased the extraordinary landscape of Eryri. The National Trust subsequently organised the event from 1984 until 2007. When the Trust could no longer support it, members of the local community established Snowdonia Marathon Cyf, a nonprofit company that now operates the race. Surplus funds are directed back into the local community, and the organisation reports donating more than Β£300,000 to local organisations and causes over a ten-year period. The event adopted the Welsh name Marathon Eryri in 2023.
