Gelli Iago via Llyn yr Adar up Allt-fawr: route map, distance and time
698 m · Snowdonia
A hard mountain walk to the summit from Croesor village car park.
Gelli Iago via Llyn yr Adar starts at about 157 m and gains 675 m over 8.8 km to 676 m on the track. The first 3 km are the easy part, averaging 8%. The steepest kilometre is the one ending at 4 km, which climbs 203 m at an average of 20%, with a 500 m stretch from 3.7 km at about 36%. The final 0.8 km eases to the top.
Gelli Iago via Llyn yr Adar at a glance
| Distance | 8.8 km one way, to the top |
|---|---|
| Climb on the track | 675 m up, 159 m down on the way |
| Start and top of the track | 157 m to 678 m (summit 698 m) |
| Steepest 500 m | About 36%, from 3.7 km |
| Steeper than 1 in 5 | 9% of the way |
| Grade | Hard |
| Start | Croesor village car park, LL48 6SR |
| Start grid reference | SH 631 446 |
| Summit grid reference | SH 681 474 |
| Parking | Croesor village car park (SH631446); the postcode is approximate |
Gelli Iago via Llyn yr Adar map
The track from the start (green) to the summit (blue), with a marker at each kilometre.
Height profile and getting to the start
Near the start
From OpenStreetMap, within 2 km. Check opening times before you rely on them.
Download the Gelli Iago via Llyn yr Adar GPX
Ascent only: plan your way down. A planning track, not checked on the ground; it doesn't show safe scrambling moves. Track data © OpenStreetMap contributors (ODbL), heights from a terrain model.
Gelli Iago via Llyn yr Adar kilometre by kilometre
Height, climb and average gradient for each kilometre of the track, with a grid reference at the end of each one to check your position on the map.
| At | Height | Climb | Gradient | Grid ref |
|---|---|---|---|---|
| 1 km | 250 m | +93 m | 9% | SH 630 454 |
| 2 km | 316 m | +66 m | 7% | SH 634 461 |
| 3 km | 381 m | +65 m | 7% | SH 637 471 |
| 4 km | 585 m | +203 m | 20% steep | SH 643 465 |
| 5 km | 629 m | +44 m | 4% | SH 651 471 |
| 6 km | 594 m | -35 m | -4% | SH 657 477 |
| 7 km | 653 m | +59 m | 6% | SH 666 480 |
| 8 km | 612 m | -40 m | -4% | SH 674 476 |
| 8.8 km | 676 m | +64 m | 8% | SH 681 474 |
How long Gelli Iago via Llyn yr Adar takes
| Pace | To the top | There and back |
|---|---|---|
| Brisk 6 km/h, 8 min per 100 m up | 2h 20m | 3h 50m |
| Steady (Naismith) 5 km/h, 10 min per 100 m up | 2h 55m | 4h 40m |
| Relaxed 4 km/h, 12 min per 100 m up | 3h 35m | 5h 45m |
Times leave out stops. Coming down the same way, the table counts the ascent once; steep descents on rough ground can be as slow as the climb.
Allt-fawr summit weather for this route
-
Good Today Sunday 18 October
Partly cloudy, up to 7°C at the summit, feeling as cold as -3°C, summit wind 19 mph gusting 26 mph, 0% chance of rain. Rated Good. Sunrise 07:47, sunset 18:14.
-
Marginal Tomorrow Monday 19 October
Slight rain, up to 8°C at the summit, feeling as cold as -2°C, summit wind 30 mph gusting 38 mph, 34% chance of rain. Rated Marginal. Sunrise 07:49, sunset 18:12.
Best day of the next seven for Gelli Iago via Llyn yr Adar: Sunday 18 October, with summit gusts around 26 mph and a 0% chance of rain.
Hour-by-hour Allt-fawr forecast
Before you go, also check: MWIS Snowdonia forecast · Met Office mountain forecast.
What to take today
- An insulated jacket, hat and warm gloves: it feels like -3°C on top.
- A waterproof jacket. It can rain on the tops in any forecast.
- Map and compass, and the skills to use them. A phone is a backup, not a plan.
- A head torch, food, water, a charged phone and a small first aid kit.
About Allt-fawr
More about Allt-fawr, with the live forecast.
Challenges that include Allt-fawr
More walks from Croesor village car park
Routes in Peakify's guides that start within 500 m of this one, for another day from the same car park.
- Croesor via the south-west ridge up Cnicht
- Rhosydd and the north ridge from Croesor up Cnicht
- Croesor via Moelwyn Bach and Moelwyn Mawr up Cnicht
- From Croesor by the north-west ridge up Moelwyn Mawr
- Croesor via Moelwyn Bach and Craigysgafn up Moelwyn Mawr
- South-west ascent from Croesor up Moelwyn Bach
- Croesor via Cnicht south-west ridge up Cnicht North Top
- Croesor via Moelwyn Mawr up Craigysgafn
- Croesor via Moelwyn Mawr up Moel-yr-hydd
- Gelli Iago via Llyn yr Adar up Moel Druman
- Gelli Iago via Llyn yr Adar up Ysgafell Wen
- Gelli Iago via Llyn yr Adar up Ysgafell Wen North Top
Other routes up Allt-fawr
| Route | Distance | Ascent | Time up | Grade |
|---|---|---|---|---|
| Crimea Pass and Moelwynion ridge | 2.7 km one way | 340 m | 1h 5m | Hard |
In an emergency
Call 999, ask for the police and then mountain rescue. Give your location (the start is at SH 631 446, the summit at SH 681 474), what happened and how many are in your group. If you have no signal for a call, a text to 999 works once you have registered your phone with emergencySMS: text "register" to 999 before you go.
Gelli Iago via Llyn yr Adar: questions and answers
How far is Gelli Iago via Llyn yr Adar?
Gelli Iago via Llyn yr Adar is 8.8 km one way to the summit of Allt-fawr. There and back by the same way is about 17.6 km.
How steep is Gelli Iago via Llyn yr Adar?
The steepest 500 m averages about 36%, starting 3.7 km from the start, and 9% of the way is steeper than 1 in 5. Gelli Iago via Llyn yr Adar climbs 675 m in all on the track.
Where do you park for Gelli Iago via Llyn yr Adar?
Gelli Iago via Llyn yr Adar starts from Croesor village car park (postcode LL48 6SR). The grid reference is SH 631 446. Croesor village car park (SH631446); the postcode is approximate
Is Gelli Iago via Llyn yr Adar suitable for beginners?
Not as a first mountain. Peakify grades it Hard: steep, rough ground where a slip matters. Build up on an easier route first.
Is there a GPX for Gelli Iago via Llyn yr Adar?
Yes. Download it from this page. It is an ascent-only planning track from the start to the summit, plotted on OpenStreetMap paths and not checked on the ground.