Eryri by UTMB®, live.

Slate quarries, scree and the summit of Wales

Five mountain races around Llanberis, on ground the organiser describes as scree, exposed ridges, boggy moorland and old slate workings.

Eryri by UTMB is held from Friday 14 to Sunday 16 May 2027 in Eryri National Park, North Wales. The Eryri 100M starts in Llanberis at 14:00 on Friday: 163 km and 9,200 m of ascent with a 48-hour maximum. The Eryri 80K starts at 20:00 the same evening in Caernarfon, 78 km and 2,500 m, in 16 hours. Saturday has the 100K at 05:30, 108 km and 5,800 m in up to 32 h 30, and the 50K at 08:30, 56 km and 3,400 m in 14 hours. The 25K closes the weekend at 08:30 on Sunday, 25 km and 1,300 m in 5 h 30. All but the 25K, whose finish the page does not state, end in Llanberis.

The organiser calls the 100M a grand tour of Eryri. It crosses Yr Wyddfa, the highest peak in Wales, passes Llyn Gwynant and Llyn Idwal, and runs through Capel Curig, Dolwyddelan, Blaenau Ffestiniog, Croesor, Beddgelert, Rhyd Ddu and Betws Garmon. The ground is technical: scree fields, boulder-strewn paths, exposed ridges, boggy moorland and the remains of the slate industry. The 80K is the odd one out, starting by the sea at Caernarfon with a fast, runnable opening before climbing towards Yr Wyddfa and descending into Llanberis.

The 100M and the 80K both run through Friday night, so a lot of this weekend is run in the dark, between villages and over high ground where a phone can lose signal. The runner can share a link to their own Livebib broadcast; family and friends open it in a browser, no account and no app, and see the position on the course line, distance covered and a finish estimate that updates as the race goes. When the signal drops in a valley or on a ridge, the position is carried forward along the course and marked as estimated instead of freezing. The runner decides who gets the link.