How far is the Eryri 100K?

The Eryri 100K is one distance: 100K (62.1 miles).

Is the Eryri 100K course marked?

Yes, the course is marked. Navigation skills are not required.

Eryri 100K

Llanberis, GwyneddNo date announced yet

A hundred kilometres of the Snowdonia massif.

100K

62 miles

mountainfellMarked course

Nobody has reviewed this one yet

No reviews of the Eryri 100K, and nothing on what people wore. Both are things no organiser publishes and every runner wants before they enter — how it actually went, and what was on your feet.

Ran it? Write the first review

Running it soon? Connect Strava and we will ask you about it the day you finish, so you do not have to remember to come back.

The course

What you’re in for

A hundred and six kilometres out of Llanberis with 5,400 m of ascent, off at half five on the Saturday morning, through Dolwyddelan, Blaenau Ffestiniog, Rhyd Ddu and Beddgelert. Technical scree, rocky path and a bit of scrambling, past glacial lakes and through remote valleys, with runnable stretches in between the climbing. Thirty-two and a half hours.

Partner · affiliate policy

Train for it: routes near the start

Routes starting within 20 km of Llanberis, Gwynedd, nearest first. Each one has a free GPX file and a TRP grade, so you can rehearse the ground before race day.

EXPERT

Snowdon, Grib Goch, Glyder Fawr, Y Garn & Elidir Fawr from Llanberis Trail Running Route

29.1km · 2,306m climb · Loop · 0.2km away

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.

Checked Jul 2026

VERY HARD

Yr Wyddfa via Llanberis Path

16.2km · 959m climb · Out & back · 0.2km away

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.

EXPERT

Yr Wyddfa via Miners' Track, Pyg Track and Crib Goch

12.0km · 710m climb · Loop · 8.5km away

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.

All Eryri (Snowdonia) routes →

Other races near here

Eryri (Snowdonia) races →

Races from other organisers starting within 30 km of Llanberis, Gwynedd, nearest first.

Jul

2027

Snowdonia Trail Marathon Eryri

Llanberis, Gwynedd · Always Aim High Events · 0 miles away

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

Jul

2028

MTC Cerridwen

Travelodge Caernarfon, Victoria Dock, Balaclava Rd, Caernarfon, Gwynedd, LL55 1SR · Ultra Running Ltd · 6 miles away

50 miles on National Cycle Route 8 from Caernarfon to Barmouth

50 miles

Navigation required

Not open yet

£90–£155

Jun

2027

Pilgrims Trail 60

Bangor Cathedral · Black Sheep Events · 7 miles away

Sixty pilgrim miles of the North Wales Pilgrims Way from Bangor Cathedral to Aberdaron inside twenty-four hours, with a tracker, seven checkpoints and the waymarkers to follow.

60 miles

Entries open

£109–£119

Jul

2027

Ogwen | Yr Helgi Du

Plas y Brenin, Capel Curig, Conwy · Always Aim High Events · 9 miles away

Fifteen, twenty-five or forty kilometres over the Glyderau and Carneddau from Plas y Brenin, with Grade 1 scrambling on the longest.

15, 25 & 40 kmup to 2,363 m climb

VERY HARD TO EXPERT

Entries open

How to enter

No date announced for the next running yet. Eryri by UTMB’s site ↗ is where it will show up first.

Common questions

: The Eryri 100K is one distance: 100K (62.1 miles).
: No course file for the Eryri 100K yet, so there's no measured climb here. When Eryri by UTMB publish one, this fills in.
: Not graded yet. A TRP grade is worked out from distance and climb measured off the course file, and there isn't one for the Eryri 100K yet.
: Yes, the course is marked. Navigation skills are not required.
: We don't hold a compulsory kit list for the Eryri 100K. Eryri by UTMB confirm mandatory kit in their race information, usually in the final instructions.
: We don't hold published time limits for the Eryri 100K. If Eryri by UTMB set cut-offs, they'll be in the race information.
: We don't hold a checkpoint list for the Eryri 100K. What's on the table varies a lot between races, so check the Eryri by UTMB race information rather than turning up expecting food.
: Not yet — we don't hold a course file for the Eryri 100K. Some organisers only send the GPX to entrants. If we get one, it goes up free, with no sign-up.
: No date announced. When Eryri by UTMB confirm the next Eryri 100K, it appears here and on the race calendar.

Eryri 100K

Nobody has reviewed this one yet

The course

What you’re in for

Train for it: routes near the start

More from Eryri by UTMB

Eryri 100M

Eryri 25K

Eryri 50K

Eryri 80K

Other races near here

Snowdonia Trail Marathon Eryri

MTC Cerridwen

Pilgrims Trail 60

Ogwen | Yr Helgi Du

How to enter

Common questions