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Brecon to Cardiff Xtreme & Taff Xtreme Marathon
1st March 2026

The Brecon to Cardiff Xtreme, is the mountain running version of our classic Brecon to Cardiff ultramarathon which is now in its 13th year.  The route is a 47.5 mile linear race over 11 peaks and high points between Brecon and Cardiff.  This is a tough winter ultra marathon with approximately 2680 meters of ascent and is only suitable for those with excellent winter mountain running skills, experience and fitness.  The event sold out in both 2024 and 2025 and places are limited.

The Taff Xtreme marathon is a linear trail marathon on the second half of the Brecon to Cardiff Xtreme ultra marathon route from Merthyr to Cardiff. This is a tough winter marathon with approximately 1300 meters of ascent and is prefect for those looking for a new winter trail running challenge or to make the leap into ultra trail running.

The Routes
Starting at the canal basin in Brecon the Xtreme heads through the old town then straight to the top of Pen Y Fan - the highest peak in South Britain.  This is followed by steep climbs up Cribyn and Fan Y Big, before a fast descent down the Roman road takes you to lower Neuadd reservoir.  Another short but steep climb reaches the Twyn Mwyalchod trig point, and is followed by a long descent towards Pontsticilli and CP2.  Here the Xtreme and Classic B2C routes briefly converge with some faster forestry running over more rolling hills, before gaining the halfway checkpoint (CP3) in Merthyr College. 

Now clear of the national park, the Classic B2C course rolls gently downhill to the finish, but the Xtreme still has approximately half the elevation to conquer!  The Xtreme runners will now be joined the the marathon runners.  From Merthyr there is a short climb over the saddle on Mynedd Aberdare which runs alongside the Gethin woodlands, followed by a fast decent and crossing of the Cynon Valley and CP4.  The route then joins the waymarked Glamorgan Way trail with a climb up towards Carn y Pigwn in the stunning St Gwynno and Llanwonno forestry complex. Checkpoint 5 is by St Gwynno Church, the resting place of Welsh legendary runner Guto Nyth Brân. After the long rolling descent of Pen y Foel, the route converges again with the B2C Classic runners and a short section along the banks of the river Taff which takes you to checkpoint 6 in Pontypridd home of the another Welsh running legend and the Honky Tronk café!  Here you can stock up on food, Welsh hospitality and Tom Jones songs before heading out into the last section of the course.  With the end nearly in sight, the X
treme runners head up and over Cefn Eglwysilan before the fast drop down into the finish and the wonderful welcome at the Coleg Y Cymoedd.

As the route is linear competitors park at the finish and are transported by coach, to the start in Brecon, or Merthyr for the Marathon course.

Event Base, Finish and Registration Location
The event base, registration and race finish is at Coleg Y Cymoedd at the following location: 
Coleg y Cymoedd
Heol Cronchendy
Parc Nantgarw
Nantgarw
CF15 7QX 

The event base provides event parking, café, large indoor area for registration, the finish line, toilets, and changing rooms.  It is easily accessible off the A470 and one junction off the M4. There are many hotels, guest houses, cafes and restaurants in the local area.  In addition there are excellent bus and rail links to and from Cardiff.

Event Starts

Xtreme
Theatr Brycheiniog,
Canal Wharf,
Brecon,
Powys
LD3 7EW

www.brycheiniog.co.uk/en

If you are going direct to Brecon car parking is in one of the many pay and display car parks outside the Theatre and more details are available here.

Marathon
Merthyr Tydfil College
Ynysfach,
Merthyr Tydfil,
CF48 1AR

There is a large pay and display car park alongside the college in Merthyr.

Map and Gps
An interactive map and gps file is available at the link at the bottom of the page.
To download the gps click on 'actions', then 'export' and follow the onscreen prompts. 

Navigation
This is an extreme mountain challenge, and the route is unmarked.  There will be some additional markings provided where the route converges with the classic B2C route, and some additional signs in the dense forest sections, but you must expect to be self-sufficient in terms of navigation throughout. Navigation is using the gps trace and we recommend a primary device such as gps watch or handheld unit and a backup app on the phone such as outdoor gps. 

Checkpoints
There are 6 manned checkpoints for the B2C Xtreme and 3 for the Taff Xtreme Marathon.  All of which provide water, energy drinks, squash, sweets, biscuits, oranges, crisps.  The halfway checkpoint (CP3) is indoors at Merthyr College in the town centre and is a great location to meet friends and family and B2C Xtreme runners will have access to your drop bag and some time to get sorted, changed and ready to take on the final half!  Details of where the checkpoints are can be seen on the FAQ page.  The link is at the bottom of this page.  Checkpoints locations can also be seen on the interactive map on map link below.

Transport

B2C Xtreme:- As the route is linear you will park your car at Cardiff (Nantgarw) race HQ and catch one of the busses (included in your entry fee) to the start of the event in Brecon. The B2C Xtreme busses leave Nantgarw Race HQ at 0530 on Sunday morning.

Taff Xtreme:- The route is linear and you have a choice of organising drop off at the start or adding coach transport to your entry and parking your car at Cardiff (Nantgarw) race HQ and catching one of the busses to the start in Merthyr. The Taff X marathon busses leave Nantgarw Race HQ at 0830 on Sunday morning.

Time Limit
The time limit for the Xtreme is 15 hours (10pm cut off).  For the Marathon the time limit is 12 hours (10pm cut off).  Only runners finishing WITHIN the time limit will be eligible for a finishers medal. However, there is an option for Xtreme runners of dropping to the classic route at merthyr if you are feeling under the weather or have missed the cut off.

Compulsory Kit
There is a compulsory kit list that must be carried which can be viewed here

Timetable -including Start, Coach Pick up and Registration Times
Saturday
1600-1900 Registration in Nantgarw

Sunday
Xtreme
0530 Bus pick up from Nantgarw and travel to Brecon
0615-0630 Registration in Brecon (only available if pre-booked and not on the bus*)
0620 Bus arrives in Brecon
0650 Race brief at Theatre
0700 Race start from Brecon
2200 Cut off time in Nantgarw

Marathon
0730-0830 Registration in Nantgarw
0830 Bus pick up from Nantgarw and travel to Merthyr
0900 Bus arrives in Merthyr
0900-0930 Tracker fitting in Merthyr
0940 Race brief on start line in Merthyr
1000 Race starts in Merthyr
2200 Cut off time in Nantgarw

Please note there is no registration on Sunday morning in Nantgarw for Xtreme runners, only for Marathon.
There is also no registration at the race start in Merthyr for the Taff Xtreme marathon runners and you must register in Nantgarw on Saturday evening or Sunday morning.

If you are going straight to the start or being dropped off and would like to register in Brecon you can book this by e-mail. You will receive a pre-race email letting you know when to do this - please don't e-mail before this date as they will need to be re-sent.

Prices
B2C Xtreme - Race entry, parking, coach transport and GPS tracking £85
Taff Xtreme Marathon - Race entry, parking at Nantgarw, and GPS tracking £45.
 
Optional extras;
Custom unisex tech B2C X race t-shirt (£20)
Custom female fit tech B2C X race t-shirt (£20)
Custom B2C X race hoodie (£40)
RWC race buff (£5)

Taff Xtreme Marathon Coach transport from Nantgarw to Merthyr (£10).

What your entry fee includes:
Participation in a classic event
Electronic timing
Live GPS Tracking and map for friends and family to follow from Open Tracking
6 (3 for the Marathon) checkpoints well stocked with refreshments
Half way drop bag transport for B2C xtreme runners (at the Merthyr)
Finishers medal (strictly for finishers only)
Emergency First Aid and First Responder cover
Event photos
Car parking at the finish in Cardiff
Bus transport from Cardiff to Brecon on Sunday morning for the B2C Xtreme runners. 
Optional bus transport for the Taff Xtreme Trail marathon runners (£10)
Welsh weather (hopefully)

Please note: in order to keep entry fees down, support local businesses and inline with what our regular runners prefer there is no meal provided at the finish and instead competitors have a choice of purchasing food and drinks in the onsite cafe at the college or in the numerous local restaurants and fast food outlets next to the finish.

Enter
Entries open on the link below.
Enter 2026 Here Brecon to Cardiff Xtreme Map and GPS Taff Xtreme Marathon Map and GPS FAQs B2C Xtreme FAQs Taff Xtreme Marathon Terms and Conditions