OTT Marathon & 10 Mile Race

The OTT (Off The Tarmac) Trail Marathon and 10 Mile Race are challenging mountain events set within the Brecon Beacons (Bannau Brycheiniog) in Wales. Scheduled for Saturday, 16 May 2026, the event is based at Parkwood Dolygaer and features a looped course that summits some of the most iconic peaks in the region.

The event provides two distinct distances, both beginning with a pre-race safety briefing.

The marathon is a demanding mountain route that requires a steady pace to meet safety requirements.

• - Landmarks: The route takes runners over Pen Y Fan via Graig Fan Ddu, across to Fan Y Big, and eventually toward the Talybont Reservoir for the final climb up Tor y Foel.
• - The Cut-off: Marathon runners must reach Checkpoint 3 (20.5 miles) by 15:00. This is 6 hours after the start, requiring a minimum average pace of approximately 18 minutes per mile.
• - Aid Stations: The marathon features three checkpoints (7, 14.5, and 20.5 miles), while the 10-mile race has one checkpoint at mile 7.

Safety gear is strictly enforced due to the exposed mountain terrain. Both races are cupless, meaning participants must carry their own reusable cup for hydration at checkpoints.

For the Marathon:

• - Hydration & Nutrition: Minimum 1 liter of water and 400 calories of emergency rations.
• - Safety Gear: Foil blanket or bivvy bag, whistle, compass, and a basic first aid kit.
• - Clothing: Waterproof jacket and trousers with taped seams, warm layer, hat, and gloves.
• - Electronics: Fully charged mobile phone and a head torch.

For the 10 Mile Race:

• - Essentials: Waterproof jacket and 500ml of water.
• - Safety: Bivvy or foil blanket and a first aid kit.

Registration for the 2026 event opens on Sunday, 27 July 2025, and closes on May 9, 2026. All finishers receive a bespoke OTT Trail Marathon coaster and a buff to commemorate their achievement in the Brecon Beacons.

The event location is Parkwood Dolygaer, Merthyr Tydfil (CF48 2UR). Participants should be prepared for mountain weather and can look forward to a variety of cakes provided at the various aid stations along the course.