OTT Marathon
Dol-y-Gaer, United Kingdom • 16 May 2026
OTT Marathon & 10 Mile Race
The event offers two distances: a looped trail marathon of around 26.2 (ish) Miles and a 10 Mile race. Both start and finish at Parkwood Dolygaer in Merthyr Tydfil and take place within the Brecon Beacons. The marathon route includes climbs and mountain trails, passing Pen Y Fan from Graig Fan Ddu, Fan Y Big, Talybont Reservoir and the final climb up Tor y Foel. The 10 mile course follows the marathon route to Checkpoint 1 then returns to Dolygaer on forestry tracks.
There are three checkpoints on the marathon course and one checkpoint for the 10 mile race. The marathon has a cutoff of six hours at 20.5 miles. All marathon finishers receive a OTT Trail Marathon coaster and buff.
Entries open 27 July 2025 and close 9 May 2026. Minimum age is 18 on the event date. Entry fees listed include UKA and non-member prices for each distance.
Compulsory marathon kit includes a charged mobile phone, minimum 1 L hydration, foil blanket or bivvy bag, 400 kcal emergency rations, basic first aid kit, head torch or torch, compass, whistle, waterproof jacket and trousers with taped seams, warm layer with hat and gloves, and a rucksack plus reusable cup. Compulsory 10 mile kit includes a first aid kit, bivvy or foil blanket, 500 ml water, waterproof jacket and a reusable cup. Visit the organization's website for the most recent information.