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Trail running routes in Eryri (Snowdonia)

Wild Welsh mountains and some of the most technical ground on these islands, from the Llanberis Path to Crib Goch.

4
Routes
18.2km
Avg distance
5,019m
Total ascent

Areas

Betws-y-CoedCadair IdrisLlanberisSnowdon

Our picks: Best trail runs in Snowdonia →

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4 routes

VERY HARD
Cadair Idris, Mynydd Moel and Craig Lwyd Circular
15.6km · 1,044m climb · Loop
You get the full horseshoe around one of Snowdonia's most dramatic cwms rather than a straight there-and-back to the summit, so the mountain's best feature - the cliff-ringed bowl at its heart - is in view for most of the route.
No car neededDog friendly
EXPERT
Snowdon, Grib Goch, Glyder Fawr, Y Garn & Elidir Fawr from Llanberis Trail Running Route
29.1km · 2,306m climb · Loop
Crib Goch is one of the most exposed ridges in Britain, and this route puts it in the middle of a big mountain day rather than as the whole objective, so you get the scramble and a proper crossing into the Glyderau either side of it.
Fell runNo car needed
Checked Jul 2026
VERY HARD
Yr Wyddfa via Llanberis Path
16.2km · 959m climb · Out & back
It's the most runnable line to the summit of Yr Wyddfa, following the rack railway most of the way up, so you can move fast on genuinely good underfoot conditions rather than picking through rock.
No car neededDog friendly
EXPERT
Yr Wyddfa via Miners' Track, Pyg Track and Crib Goch
12.0km · 710m climb · Loop
Most people treat the Miners' and Pyg Tracks as a straightforward there-and-back pairing, but this GPX shows the loop actually crossing Crib Goch, which changes the entire character of the day.
Fell runNo car needed

Races in Eryri (Snowdonia)

All Eryri (Snowdonia) races →

The next races starting in Eryri (Snowdonia), with runner reviews and what people wore where we have them. Train on the routes above.

26

Sept

2026

Sea to Summit Yr Wyddfa

Caernarfon Castle, Gwynedd · Rat Race

Forty-seven kilometres from the gates of Caernarfon Castle to the summit of Yr Wyddfa.

47 km

Event full

8

May

2027

Woody's Rotary Bala Challenge

Penllyn Leisure Centre, Pensarn Road, Bala · Bala & Penllyn Rotary Club

Twenty miles with four thousand feet of climb round Llyn Tegid and the Aran ridge from Bala, or fourteen with two and a half thousand, or eight with the steam train back from Llanuwchllyn. Ten hours, 350 places, GPX files published.

8, 14 & 20 milesup to 1,219 m climb
Navigation required

Entries open

£15–£25

19

Jun

2027

Ultra Wales

Coed-y-Brenin, Gwynedd · GB Ultras

Fifty-one miles out of Coed-y-Brenin.

51 miles2,922 m climb
Navigation required

EXPERT

Entries open

10

Jul

2027

Snowdonia Trail Marathon Eryri

Llanberis, Gwynedd · Always Aim High Events

Ten kilometres to fifty-six from Llanberis, under Yr Wyddfa, with the marathon and ultra both ITRA and UTMB indexed.

10, 21.2, 43.8 & 56 kmup to 2,300 m climb

HARD TO VERY HARD

Entries open

About running in Eryri (Snowdonia)

Wild Welsh mountains and some of the most technical ground on these islands, from the Llanberis Path to Crib Goch.

Four routes, all on Yr Wyddfa or Cadair Idris. The Llanberis Path is the way up if you want a hard run rather than a scramble: 16km and 959m of climb on a clear track. The Miners' and Pyg Tracks with Crib Goch are a different proposition — the ridge is an exposed scramble and summer only. Cadair Idris from Minffordd is a 16km circuit with over 1,000m of climb, and the 29km Llanberis round over the Glyderau is a full mountain day. The Sherpa'r Wyddfa bus links Llanberis, Nant Peris and Pen-y-Pass, so you can leave the car in the valley. Every route has a free GPX download and an honest TRP Grade.

Safety reminder

In an emergency call 999 or 112 — ask for Police then Mountain Rescue.

No signal? Pre-register emergency SMS: text register to 999.

Safety guides →

Common questions

There are 4 trail running routes in Eryri (Snowdonia) on Trail Running Planet, covering 4 areas. All routes include free GPX downloads and honest grading.