Nestled within the breathtaking Brecon Beacons, the OTT Trail Marathon and 10-mile race promises an unforgettable adventure for trail runners. This challenging course showcases some of Wales' most iconic peaks and vistas. The marathon route is a loop that begins at Parkwood Caravan Site and takes you through Pen Y Fan via Graig Fan Ddu before ascending to Fan Y Big. The journey continues across Talybont Reservoir, culminating in the final climb up Tor y Foel. After this exhilarating ascent, runners head back towards the finish line. For those opting for the 10-mile race, you'll follow the marathon route until Checkpoint 1 at approximately seven miles, where you diverge onto forestry tracks leading to Dolygaer and the finish. Both races offer stunning mountain trails and panoramic views that are a highlight of this event. The aid stations provide essential hydration and energy boosts along with delicious cakes, making the journey all the more enjoyable. Upon completion, every participant will receive an OTT coaster and buff as a memento of their achievement. Competitors in both events must bring specific compulsory kit to ensure safety throughout the challenging terrain: - Marathon runners need items such as reusable cups, fully charged mobile phones, hydration packs with at least 1 liter capacity, emergency rations (400 calories), basic first aid kits, head torches or flashlights, compasses, whistles, waterproof jackets and trousers, warm layers including hats and gloves. - For the shorter race, essential items include reusable cups, a basic first aid kit, bivvy/foil blankets, 500ml of water, and a waterproof jacket. The marathon features three checkpoints at key intervals to ensure runners stay on track: 1. Checkpoint 1: At approximately seven miles. 2. Checkpoint 2 (Marathon only): Around the halfway mark at 14.5 miles. 3. Checkpoint 3 (Marathon only): Near the finish line, around 20.5 miles. The marathon has a strict cut-off time of 6 hours after the start, meaning runners must maintain an average pace faster than 20 minutes per mile to complete all checkpoints within this timeframe and reach the finish by 15:00 at Checkpoint 3. Race day starts with briefings for both events: - Marathon briefing begins at 8:50 AM. - The marathon start time is set for 9:00 AM sharp. - For the 10-mile race, there's a pre-race briefing at 9:50 AM followed by the start at 10:00 AM. Whether you're tackling the full marathon or enjoying the scenic beauty of the shorter route, this event is sure to test your limits and reward you with incredible views and memorable moments.
Races Offered
Non Member - 10 Miles
May 15, 2027
straighten
Distance —
16.1K
terrain
Type —
Running
timer
273 days remaining
sell
£25.00
Non Member - Marathon
May 15, 2027
straighten
Distance —
42.2K
terrain
Type —
Running
timer
273 days remaining
sell
£59.00
UKA Member - 10 Miles
May 15, 2027
straighten
Distance —
16.1K
terrain
Type —
Running
timer
273 days remaining
sell
£23.00
UKA Member - Marathon
May 15, 2027
straighten
Distance —
42.2K
terrain
Type —
Running
timer
273 days remaining
sell
£57.00
Weather History
These values represent the 3-year monthly averages for May in Merthyr Tydfil.
thermostatTemperature
8.9° / 16.3°
wb_sunnyFeels like
5.9° / 13.4°
light_mode
Avg sunshine hours
10h 54m
water_drop
Avg rainfall
3.1 mm
ac_unit
Avg snowfall
—
air
Avg wind speed
13.6 km/h (Gentle breeze)
opacity
Sweat loss rate
Low
terrain
Course conditions
Firm and slightly soft
sunny
Max UV Index
Moderate (4.2)
humidity_mid
Humidity
78.8%
wb_twilight
Sunrise
05:20
nightlight
Sunset
21:00
About Merthyr Tydfil
Learn more about the host city, Merthyr Tydfil.
Merthyr Tydfil is a town and County Borough in South Wales in the historic county of Glamorgan on the southern edge of the Brecon Beacons National Park.