Trail Running calendar near Harwell 2025-2026

We have found 348 Trailruns within 80 miles of Harwell. See below where and when you can find the races.

The Reigate Priory Park 10K is a scenic charity fun run held in Priory Park, Reigate, Surrey. The course features a 250-meter start plus four laps on an accurately measured, gently undulating cross-country terrain surrounded by lush greenery. Suitable for runners of all levels, the event fosters a f..

Farmmageddon is an endurance running event held at Hyde Hall Farm, Buntingford, SG9 0RU. Returning for its second year, the event features a challenging 100-mile race completed over 32 hours across two days. The course consists of a 5.3 km loop combining trail, grassland, and some tarmac paths, suit..

The London 2 Brighton Ultra Challenge is a premier endurance event in the UK, offering multiple distances including 100km, 75km, 58km, 42km (Sussex Marathon), 25km, and a 10km option. Starting mainly from Richmond-Upon-Thames, participants traverse the scenic North Downs and Surrey & Sussex countrys..

The Three Castles 50km Ultra Marathon is a scenic race held in Kent, England, starting in Rochester and finishing at Tonbridge athletics track. The flat course follows the River Medway, passing three medieval castles, charming villages, and lush countryside along the Medway Valley Walk. Runners expe..

The Beat the Sunset 50km ultramarathon takes place in Maidenhead, Berkshire, starting and finishing at the NMCC Sports Club. This multi-terrain course is fully marked and features four checkpoints approximately every 10km, with a personal nutrition drop available in the latter half. The event offers..

The Ridgeway Challenge is an 86-mile (139 km) point-to-point trail running race along the entire length of The Ridgeway National Trail in England. Starting at Ivinghoe Beacon in Hertfordshire and finishing at the Avebury Stones in Wiltshire, the course follows a historic path that has existed for ov..

UTMB Index

The Circuit du Sore Legs is a unique running event held at Wodson Park Sports and Leisure Centre in Ware, Hertfordshire. Participants run on a traffic-free 400-meter athletics track, with distances ranging from 5k to a 6-hour challenge, including half marathon, full marathon, and 50k ultra options...

June 2026

The Two Tunnels Races, held in Bath, UK, offer a unique running experience featuring the longest underground sections in the UK. The course passes through the historic Devonshire Tunnel (408m) and Combe Down Tunnel (1672m), both well-lit and surfaced, providing a flat and scenic route beneath the ci..

BigSea Trails (WATER) is a trail running event held on the Isle of Purbeck, Dorset, starting and finishing on the sandy Knoll Beach at Studland. Part of the Classic Element Trail Series, this race celebrates the element of water with routes that showcase stunning coastal and countryside scenery, inc..

The Centurion South Downs Way 100® is a challenging 100-mile non-stop ultramarathon held annually in Southern England, following the entire South Downs Way National Trail. Starting near Winchester and finishing in Eastbourne, the course features rolling chalk ridgeways, ancient forts, picturesque vi..

The Cotswold Way Ultra Challenge is a premier endurance event held in the scenic Cotswolds, UK, featuring multiple distance options including 100km, 75km, 50km, 25km, and a 10km run in Cirencester. Participants can walk, jog, or run at their own pace on a looped route starting and finishing at Ciren..

The Centurion South Downs Way 50km is a challenging non-stop trail race held within the South Downs National Park in Southern England. Starting near Winchester at Matterley Bowl, the 50km course follows the scenic chalk ridgeway, primarily along the South Downs Way National Trail, and finishes at Qu..

The Nene Valley Trail Run is a friendly and scenic off-road running event held at Castle Farm Campsite in Fotheringhay, near Peterborough. Scheduled for June 13, 2026, it offers two race distances: 10 and 20 miles. The courses traverse picturesque Northamptonshire countryside, including green fields..

The Cheddar Gorge Challenge is a scenic running event held at Warren Farm, Somerset, within the Area of Outstanding Natural Beauty of the Mendip Hills. Participants can choose from various distances including 1km, 3km, 6km, 10km, half marathon, and marathon, with routes featuring breathtaking views..

Beyond Trails London is a trail running event set in Greater London, offering two distances: a 25km trail and a 55km ultra. The routes follow parts of the Capital Ring footpath, showcasing iconic landmarks such as Eltham Palace, Wimbledon Common, and Richmond Park, alongside hidden trails, parks, wo..

The Dunstable Downs Half Marathon is a rugged, off-road trail running event held at the National Trust's Dunstable Downs estate in the UK. Covering 21.2 km with over 450 meters of elevation, the course features chalk ridge trails offering stunning ridgeline views, challenging hills, exhilarating des..

The Cock-a-doodle Dawdle is a trail running event held at the scenic Hyde Hall Farm in Buntingford, Hertfordshire. Now in its third year, the race offers multiple distance options including 5K, 10K, half marathon, full marathon, and ultra marathon, catering to runners of all levels. The course featu..

The RunThrough Marlow Trail Run, taking place on June 28, 2026, is a scenic off-road event set in the Thames Valley, starting at Marlow Rugby Union Football Club. It offers three distances: Half Marathon (1 lap, 53m elevation), 10K (1 lap, 23m elevation), and 5K (2 laps, 20m elevation), all on trail..

July 2026

The Birmingham Black Country Half Marathon is a running event held in the Black Country area near Birmingham. Organized by StuWeb Events Ltd., it offers participants a half marathon distance of 13.1 miles. The race takes place in a vibrant atmosphere, showcasing the local community and landscape.Whi..

Fen Gallop 2026 is a scenic running event held in Willingham, Cambridgeshire, featuring flat, multi-terrain courses along country roads, footpaths, and bridleways. Participants can choose between a 10K race or a shorter 4-mile option, both offering chip timing. The event welcomes runners aged 15 and..