2023 DATE TBD
This is one of the toughest "half marathon" routes in the UK, and probably the most awe-inspiring. The route takes you through ancient woodland, past stunning glacial lakes, historic trails, and challenging mountainous terrain, including the summit of one of Snowdonia's most iconic mountains, Cadair Idris.
This is a mountain race.
STATS
This is one of the toughest "half marathon" routes in the UK, and probably the most awe-inspiring. The route takes you through ancient woodland, past stunning glacial lakes, historic trails, and challenging mountainous terrain, including the summit of one of Snowdonia's most iconic mountains, Cadair Idris.
This is a mountain race.
STATS
- Distance: 13.1 miles
- Height Gain: 1150m
- Men's Course Record: 2h 10m 40s (Richard Shephard, 2021)
- Women's Course Record: 2h 42m 09s (Melanie Funnell, 2021)
THE ROUTE
An interactive route can be viewed on Outdoor Active here.
An interactive route can be viewed on Outdoor Active here.
DOWNLOAD GPX
Please download for your device:
Please download for your device:

Cadair_X.gpx | |
File Size: | 23 kb |
File Type: | gpx |
ROUTE DESCRIPTION
Starting from the opposite side of the lake from Tyn-Y-Cornel Hotel the route follows a country track along the north side of the stunning glacial ribbon lake, Tal Y Llyn, before entering the Cadair Idris National Nature Reserve.
You will run through the tranquil woodland of Dol Idris and then up steeply through the wooded gorge. As you ascend out of the trees you will clasp glimpses of the stunning glacial lake Llyn Cau to your left. You will continue your ascent towards Mynydd Moel before traversing west and ascending to the summit of Cadair Idris, 893m.
The section between the 3km and 6km mark involves steep ascent. The most challenging underfoot terrain is just after the summit of Cadair Idris. Take care when descending.
Once off the rocky terrain of the summit your descent will follow the established Pony Path before turning south west down towards Tyn Y Fach and Mary Jones' Chapel. You will then follow a beautiful section of the Mary Jones walk before traversing North East through tranquil woodland tracks back to Tal Y Llyn and the Tyn Y Cornel Hotel for some well earned rest.
Starting from the opposite side of the lake from Tyn-Y-Cornel Hotel the route follows a country track along the north side of the stunning glacial ribbon lake, Tal Y Llyn, before entering the Cadair Idris National Nature Reserve.
You will run through the tranquil woodland of Dol Idris and then up steeply through the wooded gorge. As you ascend out of the trees you will clasp glimpses of the stunning glacial lake Llyn Cau to your left. You will continue your ascent towards Mynydd Moel before traversing west and ascending to the summit of Cadair Idris, 893m.
The section between the 3km and 6km mark involves steep ascent. The most challenging underfoot terrain is just after the summit of Cadair Idris. Take care when descending.
Once off the rocky terrain of the summit your descent will follow the established Pony Path before turning south west down towards Tyn Y Fach and Mary Jones' Chapel. You will then follow a beautiful section of the Mary Jones walk before traversing North East through tranquil woodland tracks back to Tal Y Llyn and the Tyn Y Cornel Hotel for some well earned rest.
CAMPING
Nearest campsite is https://doleinion.com/.
Nearest campsite is https://doleinion.com/.
SCHEDULE
- 08:30 - 09:30 - Registration
- 09:50 - Race brief on start line
- 10:00 - Race start
CHECK POINTS
Distance from start, and altitude:
ON COURSE NUTRITION
The following will be available as a minimum:
It is paramount that no litter is left on the route. If you are using your own nutrition please carry out wrappers. Any participant seen deliberately littering will be disqualified and banned from future events.
Distance from start, and altitude:
- CP1: 5.1km, 625m (style)
- CP2: 7.3km, 893m (summit)
- CP3: 9km, 560m (saddle)
- CP4: 15.5km, 25m (Mary Jones' Chapel)
- CP5: 18.6km, 95m (Forest)
ON COURSE NUTRITION
The following will be available as a minimum:
- CP3: Water, energy bars
- CP4: Water, Coke, High 5 Gels, buttered & salted new potatoes
- CP5: Water, Coke, High 5 Gels
It is paramount that no litter is left on the route. If you are using your own nutrition please carry out wrappers. Any participant seen deliberately littering will be disqualified and banned from future events.
CUT OFF POINT
If you have not reached CP1 within 75 minutes of the event start time you will be asked to turnaround and return to the event start. CP1 is around the 5.2km mark, after 600m of ascent.
This cut-off is in place for the safety of participants and marshals.
If you have not reached CP1 within 75 minutes of the event start time you will be asked to turnaround and return to the event start. CP1 is around the 5.2km mark, after 600m of ascent.
This cut-off is in place for the safety of participants and marshals.
COMPULSORY KIT
Your usual hill running kit must include:
*Collapsible silicone race cups are available to purchase at registration for £5.
In the event of severe mountain weather we'll use our Plan B route.
Your usual hill running kit must include:
- Waterproof jacket
- Insulation layer (eg micro-fleece, light gilet)
- Race-cup*
- Suitable bag for carrying kit
- Whistle
- Fully charged mobile phone (waterproofed)
- Suitable footwear
- Map/GPS + Compass
- Hat/buff
*Collapsible silicone race cups are available to purchase at registration for £5.
In the event of severe mountain weather we'll use our Plan B route.
RACE HQ
The Tyn Y Cornel Hotel, Gwynedd LL36 9AJ. All participants must have the Hotel number stored - 01654 782 282.
The Tyn Y Cornel Hotel, Gwynedd LL36 9AJ. All participants must have the Hotel number stored - 01654 782 282.
PARKING
Please park in the lay-bys along the lake. Please do not park in the Tyn Y Cornel Hotel car park unless you are booked for a meal, or have booked a room. If you are going to eat on the Hotel picnic benches, please buy food/drink from the Hotel.
There is all day parking (£5) available and overnight parking (£10) available at the Pen Y Bont Hotel, 1 minute's walk away!
If you can please car share.
Please park in the lay-bys along the lake. Please do not park in the Tyn Y Cornel Hotel car park unless you are booked for a meal, or have booked a room. If you are going to eat on the Hotel picnic benches, please buy food/drink from the Hotel.
There is all day parking (£5) available and overnight parking (£10) available at the Pen Y Bont Hotel, 1 minute's walk away!
If you can please car share.
COURSE RECORDS
Our organic cotton Cadair X Hoodie is available here, and the T-Shirt is here.
- Richard Shephard 2:10:40 (June 2021)
- Melanie Funnell 2:42:09 (June 2021)
Our organic cotton Cadair X Hoodie is available here, and the T-Shirt is here.
What They Said...
The debut of CADAIR X took place on 13th July 2019 with great success. Thanks to all that took part and those that helped make it happen, not least the fabulous marshals, The Tyn Y Cornel Hotel and Natural Resources Wales.
"Just wanted to say how much I enjoyed the Cadair X half marathon last week, it was so well organised and such a beautiful course. And the fact that their was no plastic and as little impact on the mountain as possible was awesome." - Nolwenn
"What a day!!! Just wanted to say how much I enjoyed Cadair X and what a great event you organised. It was really enjoyable - yes, all 1,150 metres of up and then down - such a friendly, supportive and relaxed atmosphere. It was my first proper ‘off road’ run and will definitely not be my last. It was much more friendly than road races and the ‘ups’ give you a chance to chat to fellow runners." - Duncan
"A week on from last weekend's event and I just wanted to say thank you for a great race. My friend and I traveled from Cambridge to come and take part and we both thoroughly enjoyed it. All the marshals were super friendly and welcoming (especially the two young ladies at checkpoint 4, which reminded me so much of being at home in South Africa. It was a real pleasure to be a part of the debut of Cadair X. It made my first experience of Wales that more memorable." - Nikara
"What can I say?! It was absolutely amazing (brutal) but such a beautiful route I will definitely be doing it next year and can’t wait to enter so I don’t miss out." - Darren
The debut of CADAIR X took place on 13th July 2019 with great success. Thanks to all that took part and those that helped make it happen, not least the fabulous marshals, The Tyn Y Cornel Hotel and Natural Resources Wales.
"Just wanted to say how much I enjoyed the Cadair X half marathon last week, it was so well organised and such a beautiful course. And the fact that their was no plastic and as little impact on the mountain as possible was awesome." - Nolwenn
"What a day!!! Just wanted to say how much I enjoyed Cadair X and what a great event you organised. It was really enjoyable - yes, all 1,150 metres of up and then down - such a friendly, supportive and relaxed atmosphere. It was my first proper ‘off road’ run and will definitely not be my last. It was much more friendly than road races and the ‘ups’ give you a chance to chat to fellow runners." - Duncan
"A week on from last weekend's event and I just wanted to say thank you for a great race. My friend and I traveled from Cambridge to come and take part and we both thoroughly enjoyed it. All the marshals were super friendly and welcoming (especially the two young ladies at checkpoint 4, which reminded me so much of being at home in South Africa. It was a real pleasure to be a part of the debut of Cadair X. It made my first experience of Wales that more memorable." - Nikara
"What can I say?! It was absolutely amazing (brutal) but such a beautiful route I will definitely be doing it next year and can’t wait to enter so I don’t miss out." - Darren
VOLUNTEER
All volunteers receive a guaranteed free entry to CADAIR X for the subsequent year. We are looking for marshals who are happy in the hills, and marshals who are happy to stay in the valley.
All volunteers receive a guaranteed free entry to CADAIR X for the subsequent year. We are looking for marshals who are happy in the hills, and marshals who are happy to stay in the valley.
CADAIR X is a WESWIMRUN Event.

2021_Results.pdf | |
File Size: | 43 kb |
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