Llanberis, United Kingdom · Trail
Official site ↗Eryri by UTMB
A UTMB World Series weekend in Eryri, North Wales, each May, run as Ultra-Trail Snowdonia until 2026: a 163 km 100M and a 106 km 100K from Llanberis, a 78 km 80K from Caernarfon and a 56 km 50K over Yr Wyddfa.
Distances
Eryri 100M
- Distance
- 163 km (101 mi)
- Vert gain
- 9,200 m (30,200 ft)
- Start
- 2:00 PM GMT+1
- Cutoff
- 48 hr
Starts and finishes in Llanberis, from 2 p.m. Friday · WSER 2028 qualifier (sub-48:00)
Eryri 100K
- Distance
- 106 km (66 mi)
- Vert gain
- 5,400 m (17,700 ft)
- Start
- May 15, 5:30 AM GMT+1
- Cutoff
- 32 hr 30 min
Starts and finishes in Llanberis, from 5:30 a.m. Saturday · WSER 2028 qualifier (sub-28:00)
Eryri 80K
- Distance
- 78 km (48 mi)
- Vert gain
- 2,500 m (8,200 ft)
- Start
- 8:00 PM GMT+1
- Cutoff
- 16 hr
Starts beneath Caernarfon Castle at 8 p.m. Friday and finishes in Llanberis
Eryri 50K
- Distance
- 56 km (35 mi)
- Vert gain
- 3,400 m (11,200 ft)
- Start
- May 15, 8:30 AM GMT+1
- Cutoff
- 14 hr
Starts and finishes in Llanberis, from 8:30 a.m. Saturday
| Distance | Vert gain | Start | Cutoff | Notes |
|---|---|---|---|---|
| 163 km (101 mi) | 9,200 m (30,200 ft) | 2:00 PM GMT+1 | 48 hr | Starts and finishes in Llanberis, from 2 p.m. Friday · WSER 2028 qualifier (sub-48:00) |
| 106 km (66 mi) | 5,400 m (17,700 ft) | May 155:30 AM GMT+1 | 32 hr 30 min | Starts and finishes in Llanberis, from 5:30 a.m. Saturday · WSER 2028 qualifier (sub-28:00) |
| 78 km (48 mi) | 2,500 m (8,200 ft) | 8:00 PM GMT+1 | 16 hr | Starts beneath Caernarfon Castle at 8 p.m. Friday and finishes in Llanberis |
| 56 km (35 mi) | 3,400 m (11,200 ft) | May 158:30 AM GMT+1 | 14 hr | Starts and finishes in Llanberis, from 8:30 a.m. Saturday |
About
Eryri by UTMB starts and finishes in Llanberis, at the foot of Yr Wyddfa, and ran as Ultra-Trail Snowdonia until 2026; it takes the national park's Welsh name from 2027. The race was started by the British runner Michael Jones and has run since 2018. Its longest race, the 100M, starts at 2 p.m. on the Friday and covers 163 km with 9,200 m of climbing on a 48-hour limit, by Llyn Gwynant and Llyn Idwal through Capel Curig, Dolwyddelan, Blaenau Ffestiniog, Croesor, Beddgelert and Rhyd Ddu, over scree, ridges, moorland and the old slate workings.
The 100K (106 km, 5,400 m) takes the northern peaks with technical scree and some scrambling. The 80K (78 km, 2,500 m) starts beneath Caernarfon Castle at sea level on the Friday night, follows the slate-quarry tracks and climbs towards Yr Wyddfa before a night finish in Llanberis. The 50K (56 km, 3,400 m) goes over the summit of Yr Wyddfa, the highest peak in Wales. The 100M and the 100K are Western States 100 qualifiers.
Course
The 100K has a limit of 32 hours 30 minutes, and in 2026 its last finisher came home in 32:17:15. The weekend's 22 km 25K is shorter than an ultra.
How to register
Entry for 2027 opens on October 5, 2026 at 10:00, with no lottery: UTMB Index holders get the first 48 hours, and from October 7 it is open to everyone, first come, first served, until April 2, 2027 or until each race is full. There is no waiting list, and the 100M asks for a UTMB Index in the 100K or 100M category.