We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

Hey there, Don't forget to log in and join the conversation Log in


21-Jun-2019 Cardiff, UK (Wales)


Image Mask
Mountains Race Race Terrain
161KM / 100Miles
1 Day - 150 Runners

Alternate Distances: 80KM/50M

DIFFICULTY Race Difficulty Expert  

Entry From £90 GBP

The SW100 is a 100mile ultra-trail footrace starting and finishing in Cardiff, crossing the South Wales Valleys and the Brecon Beacons!

It is a demanding test of endurance over varied and challenging terrain and is only suitable for experienced and competent ultra-trail runners. The route has approximately 6400 meters of ascent and is over 90% on trails. 

The Route

The race starts in Cardiff, the capital city of Wales, briefly heading North out of the city to Castel Coch.

On a clear day, from the top of the first climb, Mynydd Y Garth, you can see the highpoints stretched out of the entire circular route you are about to conquer - even Pen Y Fan looming in the distance! From here you head West, picking up trails along the Ridgeway route towards Ogmore Vale before heading North again to the top of the Bwlch. You will cross the Valleys of the old mining communities of Treorchy and Hirwaun before heading into the Brecon Beacons National Park.

Some stunning forestry trails take you to the more exposed summits of Fan Llia and Fan Frynych, as you then drop down to cross the A470 and the Storey Arms at the half way point. The route then heads up the main Brecon Beacons Range of Corn Du, Pen y Fan, Cribyn and Fan y Big before the long descent to Talybont reservoir. From here the last big climb in the Beacons is Tor y Foel before turning back towards Cardiff via Tredegar, the Rhymney Valley and the rolling hills surrounding them. A final push over Caerphilly Mountain and Crag yr Alt brings you back to Castle Coch and a easy jog to the finish.


There will be 10 manned checkpoints with the usual variety of energy foods and drinks. The checkpoints at mile 26, 50 and 75 will provide a substantial meal option. Exact details of what you will find at each checkpoint will be provided before the race allowing you to plan an effective nutrition strategy. There will be a number of control points located on the course (for example the top of Cribyn) to ensure competitors follow the course correctly and to aid safety, they are not manned.

Time Limit

There is a 40 hour cut-off time for runners to complete the entire SW100 course. 

Route finding and navigation

The route is self navigation and you will receive a marked map with the route on it, a comprehensive road book with route description in it, and a gpx file of the route.

Organised Recces

There are four organised recce days throughout the year.

Participant entry requirements & experience

Both routes require participants to be self-sufficient, which means you must be able to complete the route as if without any support, carrying the appropriate compulsory kit and food and water beween checkpoints. To enter the SW 100 you need to have experience in Ultra trail racing and as a minimum you should have completed at leat one 50 mile event of similar nature, examples will be asked for on the entry form. You should be able to run comfortably and navigate at night. You will need to be totally self-sufficient throughout the event and able to make sound mountain judgment.

Solo, Pair or Team

You can enter the event as an individual, a pair or a team of up to four. All members of pairs or teams must complete the course staying together. There is no relay option for the course.

What your entry fee includes

  • Checkpoints with refreshments
  • Event T-shirt
  • Event Medal
  • Camping at race HQ for Friday and Saturday night
  • Toilets, showers and changing facilities
  • Post Event Meal
  • Physiotherapy and First Aid Cover

Event Organiser
Joe Timmins



Elevation: Very little change < 500 metres. Benign running terrain, not technical.

Suitable for: First ultra runners completing a marathon or doing regular long distance running in the last six months.


Elevation: Increase of up to 1000 metres

Suitable for: Runners who have completed at least one ultra distance race (or similar event) or are doing long distance running (>26 miles) regularly, with elevation shown.


Elevation: Increase of up to 1500 metres

Suitable for: Runners who have completed several ultra distances or similar events, or are doing long distance running regularly, with elevation shown.


Elevation: Increase of up to 2000 metres with some challenging climatic conditions (e.g. ice, snow, humidity or heat) and or technical terrain

Suitable for: Experienced runners who have completed at least regular ultra distances in last 12 months, or are doing regular long distance running (>50 miles) with elevation and conditions shown (where possible). Admission to these races may be subject to evidence of recent qualifying race participation and recent medical examination certificate. Check with the race organiser regarding entry requirements.


Elevation: Increase of up to 2000 metres with very challenging climatic conditions (e.g. ice, snow, humidity, heat or at high altitude) and or technical terrain.

Suitable for: Very experienced long distance ultra runners (min 3 years’ experience) or are doing regular long distance running (>50 miles) with elevation and conditions shown (where possible). Admission to these races is often subject to evidence of recent qualifying race participation and recent medical examination certificate. Purchase of specialist kit is often recommended for these races.

Endurance - Multi-activity

Type: An ultra distance race including at least two of the following activities such as running, swimming, cycling, kayaking, skiing and climbing. It may also include different climatic conditions (eg ice, snow, humidity, cold water, mud or heat).

Suitable for: Experienced multi-skilled athletes who have trained for the different activities included in this event. Admission to these races may be subject to receipt of a recent medical examination certificate. Check with the race organiser regarding entry requirements and any specialist equipment required such as a wetsuit, skis or a mountain bike.

Global - Virtual

Type: A virtual race which can be run at any time shown on the dates shown, on any type of terrain in any country.

Suitable for: For runners from beginners to experienced as you choose your own course and challenge based on the guidelines and options set by the virtual race organiser.

Review SW100

You must be logged in to add your review, click here to login or register

Comment Arrow

Peter Telford

12:47 08-07-18

I tried the 100 mile in 2018 and it is very hard - I crashed out around the 70 mile point. I trained really hard and could make all sorts of excuses - the weather was very hot, I got lost etc but when you boil it down for the 'plodders' there is little margin for error and I made too many silly mistakes. Don't be drawn into the belief that because you appear to get slightly longer (40 hours) that it is any easier - it isn't! I had trained in the Brecons but going up Pen y Fan after already doing some 45 miles was certainly a mental test.

Can it be done by plodders - certainly. But plan your race management very carefully and go mentally prepared for a tough couple of days.

As for the event - it was well run with excellent checkpoints and excellent support from the crew. After that it is down to you - it was great experience which I don't think I will repeat; but I will take that experience into other events

Comment Arrow

Sarah Wilde

08:18 14-06-16

This is a tough event with only 7 out of 27 of us finishing the inaugural 100 mile event in 2016.

The course is wonderful, taking you from the city into the rural outskirts of Cardiff, then climbing through the industrial remnants of the South Wales coalfields, through the middle of waterfall country, until you hit the Brecon Beacons. With around 9000 foot of ascent already in your legs, you then have to hit every top in the central Beacons until you get back to the valleys and head for home. The support from the Run, Walk, Crawl Team is second to none. Check points are well stocked and you will be well looked after from the volunteers, drawn from the local trail running community, who will feed you, water you and patch you up on route.

With the same mileage and similar elevation, this course compares directly with the Lakeland 100 event, and having now completed both, I'd say they were both equally challenging. The SW100 is certainly not to be underestimated!

A great event, good value for money, and one that I hope can only grow.

Have you run one of these races?

Add your race review
to the race page for your
chance to win great kit
like these

Not a member?

Join Now

It takes less than
a minute