Trail Running calendar near Harwell 2025-2026

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...

Surrey Hills Half Marathon is a guided trail half marathon based in Guildford, Surrey, covering about 13 miles. The route travels through the Surrey Hills, with highlights including St Martha's Church and hill, the village of Shere, and views from Newlands Corner and Hackhurst Downs, including secti..

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..

Two Tunnels Races in Bath, UK offer a unique city-centre running experience beneath the city via the Devonshire Tunnel (408m) and Combe Down Tunnel (1672m)—the longest underground section of any UK race. The well-lit, surfaced tunnels form a flat, shared-use path starting and finishing at Brickfield..

Dell 10km takes place in the Hampshire countryside at Dummer Down Farm, hosted by Dummer Down Brewery. The event features a 10km multi-terrain route (and a Canicross 10km) that weaves through private farmland, woodlands, fields and local lanes, finishing back at the brewery taproom. The course is ab..

Centurion Running’s South Downs Way 50km is a 50km non-stop trail ultramarathon through the South Downs National Park. The course starts at Matterley Bowl near Winchester and finishes in the Event Field at Queen Elizabeth Country Park, following the chalk ridgeway along the South Downs Way with expa..

The Cotswold Way Ultra Challenge is part of Ultra Challenge’s UK trek and trail run series. It starts from Cirencester Basecamp in the heart of the Cotswolds and offers Full 100 km, plus 75 km, 50 km, 25 km options, and a 10 km Cirencester leg. The 100 km loop threads rolling hills, villages and foo..

Friendly, scenic 10 and 20 mile trail races set in the Nene Valley countryside. Based at Castle Farm Campsite in Fotheringhay, near Peterborough (PE8 5HZ), the routes take in green fields, bluebell woodlands, rivers and disused railway tracks through quiet villages. Both distances are fully marked a..

South Downs Way 100 is a 100-mile non-stop ultramarathon along the South Downs Way National Trail in southern England. Beginning at Matterley Bowl near Winchester and finishing at Eastbourne’s athletics track, the route traverses chalk ridgeways with rolling hills, ancient forts, quaint villages, an..

The Cheddar Gorge Challenge is a demanding off-road running event held at Warren Farm, Charterhouse, Somerset, within the stunning Mendip Hills Area of Outstanding Natural Beauty. Offering distances from 1km fun runs to a full marathon, the course features diverse terrain including open fields, flat..

Wendover Woods Half Marathon & 10k, staged in Wendover Woods, Upper Icknield Way, Aston Clinton, Buckinghamshire, offers trail runners a forest challenge. The course comprises a hilly 10k multi-lap route through Wendover Wood forest, with Half Marathon option also on offer. Runners can expect scenic..

Solstice at the Lakes is a timed trail running event held at Leybourne Lakes Country Park in Kent, featuring 6-hour, 12-hour, and 24-hour race options. Participants can compete solo or in teams (pairs or up to four runners) on a flat, fast, and scenic 2.5km loop combining trail, gravel, and tarmac s..

Three Shires Way Ultra & Marathon is Race Harborough's point-to-point trail event, traversing the Three Shires Way across Buckinghamshire, Bedfordshire, and Northamptonshire. The lineup includes a 50-mile Ultra and a marathon, both run on bridleways that are well waymarked, with a Grafham Water loop..

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

P24 - The Longest Attended Day takes place at Denbies Wines Estate, London Road, Dorking, Surrey, on the summer solstice weekend of 20-21 June 2026. The concept is simple: run 1 mile on the hour for 24 hours on a flat-ish, off-road 1-mile loop through the estate. Attended participants benefit from f..

The Centaur 100 Mile Ultra, hosted by Phoenix Running, is a unique 100-mile trail running event held at Denbies Wine Estate in Dorking, Surrey. Designed for both seasoned ultra runners and first-timers, the race features a flat-ish, single 1-mile loop course through the scenic wine estate trails. Pa..

The Phoenix Denbies Marathon & Half Marathon, held at Denbies Wine Estate in Dorking, Surrey, offers a unique off-road trail running experience on a flat-ish 1-mile loop with slight inclines. Scheduled for June 2026, the event features flexible start times over a 30-hour window, allowing participant..

The Midsummer Munro will take place in Walton on the Hill on Sunday 21 June 2026. You can run 13 miles.

Dunstable Downs Half Marathon is a scenic trail race set in the National Trust’s Dunstable Downs estate. In its sixth edition (2026), the 21.2km course with about 450m of ascent mixes ridge views, fast descents and climbs. The route begins at the National Trust Countryside Centre, visits Tree Cathed..

Run The Seasons at Cowdray is a late-June running event on the Cowdray Estate near Midhurst, with race HQ and parking at the Cowdray Farm Shop & Café. Runners can choose from 5km or 10km routes, including a dog-friendly canicross option, circling the Cowdray Polo Lawns and heading out to Ambersham C..