Marathon Eryri, still widely known as the Snowdonia Marathon, is one of the toughest and most loved road marathons in Britain. The course makes a full loop around Yr Wyddfa (Snowdon), starting and finishing in Llanberis, and it has been run for more than four decades. Whether you are hoping to race it or coming to cheer someone round, this Marathon Eryri race day guide covers how entries work, road closures, where to watch, getting there and where to stay.
When is it?
It is held in late October each year (the 2026 race, the 42nd edition, was set for Saturday 24 October with a 10.30am start). Check marathoneryri.com for next year’s date and ballot before booking travel or accommodation.
The route in brief
The race climbs the Llanberis Pass to Pen-y-Pass, drops through Nant Gwynant to Beddgelert, heads north past Rhyd Ddu to Waunfawr, then makes the final climb to Bwlch y Groes before a steep descent to the finish on Llanberis High Street. For the full breakdown, with heights, total ascent and the race’s history and records, see our guide to the Snowdonia Marathon course. If it is your first go, our Marathon Eryri training guide covers hill sessions, pacing and a course recce.
On race day there are twelve feed stations with water, several also offering energy drink and gels. The organisers publish a course map, elevation profile and GPX file on the race route page of the official site, which is also handy for supporters planning where to stand.
How to get an entry
For the 2026 race, entry was by ballot. It opened for one week in early December 2025, each person could apply for one place only, and results were sent out in January with a short window to pay. Unclaimed places went to a second draw and there is a waiting list. There is no good-for-age entry; places are spread across age categories. Transfers were allowed within set dates.
Some charities also hold places in return for fundraising. Watch the official website and its social channels from late autumn for news of the next ballot. Junior races also take place on race weekend. For other events that month, see our guide to autumn running in Eryri. If you miss out in the ballot, the Snowdonia Half Marathon at Llanrwst is a shorter hilly race held in spring.
Where to watch
The organisers are honest that the geography of the course makes spectating difficult, as much of it runs along roads that are closed or one-way on race day. Good options are:
- Llanberis: the start and the finish are both here, so you can see runners off, have lunch and be back on the High Street for the finish.
- Beddgelert: a lovely village to wait in, with cafés, though the A498 through the village is closed for part of the race.
- Waunfawr: around mile 22, just before the final climb, where support is most needed.
For the 2026 race, the race-day information page listed closures including a rolling closure over the Llanberis Pass, a closure through Beddgelert with traffic from Caernarfon diverted at Rhyd Ddu, a closure in Waunfawr and Llanberis High Street closed for most of the day. Check the official race-day page for the current year’s times before you plan a route around the course.
Tips for supporters
- Pick one or two spots, not five: with roads closed or one-way, trying to chase runners round the loop by car rarely works. Llanberis plus one other point is realistic for most people.
- Agree a meeting point: the finish area on the High Street gets very crowded, and mobile signal around the passes and in busy crowds can be patchy, so fix a place to meet beforehand.
- Bring warm kit for your runner: a dry layer, hat and something to eat make a big difference once they stop, especially if the weather has turned.
- Dress for the mountains yourself: standing still at the roadside in late October is cold work, so bring waterproofs and a flask.
- Make some noise: the final climb from Waunfawr is where runners most need the encouragement.
Getting there and parking
Llanberis has several pay and display car parks within walking distance of registration, and the organisers ask everyone to share transport where possible. Buses run between Bangor or Caernarfon and Llanberis. Our parking and transport guide has more on getting around the area.
Where to stay
Book early: Llanberis fills up on race weekend, and many runners stay in Caernarfon, Bangor, Beddgelert or Betws-y-Coed. Our where to stay guide covers the main bases, and our pick of the best hotels in Caernarfon suits runners staying on the coast. If you have a spare day, the Snowdon Mountain Railway is a gentle way to see the mountain you just ran round, or read up on the summit itself in our Yr Wyddfa guide.
You will hear plenty of Welsh in Llanberis. A shout of dal ati! (keep going!) from the roadside is a good one to learn.
FAQs
Is the Snowdonia Marathon the same as Marathon Eryri?
Yes. The race now goes by the name Marathon Eryri, but it is the same event and the same loop around Yr Wyddfa from Llanberis.
Does the marathon go up Snowdon?
No. It goes around the mountain on roads and tracks, with its highest point at Bwlch y Groes, around 1,200ft, near the end.
Is there a cut-off time?
Yes, there has been a time cut-off at Waunfawr, around mile 22, before the final climb. Check the current year’s race information on the official site for the exact time.
Can I enter on the day?
No. Places are allocated in advance through the ballot and transfer system, so watch the official site for when the next ballot opens.
