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 Bath 50 Ultra Challenge is a premier trekking and trail running event held in the historic city of Bath, UK. Participants can choose from three looped distances: 50 km, 29 km, or 10 km, all starting and finishing at Bath Racecourse. The course offers scenic panoramic views, passing iconic landma..

The Run the Wild Half Marathon - Spring Edition is a 13-mile (21.1 km) trail running event set in the scenic Chiltern Hills, just 40 minutes northwest of London near Tring. Featuring rolling chalk hills and woodland paths with around 300m of ascent, the course offers a welcoming atmosphere for all a..

The Bristol Trail & Ultra, held on 28 March 2026, is a trail running event in Bristol offering two distances: a 25km trail and a 55km ultra. Both races start and finish at Museum Square in the city center. The routes take runners off the tarmac through woodland, riverside paths, parks, and disused r..

Ultra In The Black Country is a scenic 32-mile ultra running event held at Baggeridge Country Park near Dudley, West Midlands. The course is a mostly traffic-free urban loop featuring disused railway lines, canal towpaths, tunnels—including the 2.7km Netherton Tunnel—and woodland areas, offering a u..

The Springtide 50k is an ultra running event held in the historic town of Arundel, West Sussex. This single-loop course offers a runnable, non-technical route through the scenic South Downs, making it ideal for beginners and experienced runners alike. Participants enjoy stunning views of rolling hil..

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April 2026

The Testway Ultra is a challenging ultra marathon held in Hampshire, England, featuring 40 and 50-mile distances along the scenic Testway footpath. The route stretches from the chalky downs near the Northern Hampshire/Berkshire border to the southern town of Totton in Southampton, showcasing picture..

The Mortimer 10km is a scenic trail running event held in the charming Berkshire village of Mortimer, starting and finishing at Mortimer Fairground. The race features a beautiful two-lap, multi-terrain course that covers woodland trails, footpaths, and bridleways with an elevation gain of 85 meters...

The Henley River Half Marathon, 10k & Junior Race takes place in April 2026 at Temple Island Meadows, Henley-on-Thames, UK. This scenic event features a mixed-terrain, undulating course along the Thames, starting and finishing at the iconic Royal Henley Rowing Regatta launch point. The half marathon..

The Rose of the Shires Ultra is a 54-mile circular ultra marathon held in Northamptonshire, starting and finishing at Brixworth Country Park. The course features approximately 70% trails, including country paths, towpaths, and forest tracks, and 30% road, with an elevation gain and loss of about 706..

The Centurion South Downs Way 50® is a challenging 50-mile ultramarathon held annually in Southern England, starting in Worthing and finishing with a lap at Eastbourne Sports Club Athletics Track. The course follows the South Downs Way National Trail, featuring 5,700 feet of elevation gain over 85%..

The Rosebud Marathon is a scenic 26.2-mile race held in Northamptonshire, England, featuring a mix of approximately 60% trails and 40% roads. Starting at Hartwell and finishing at Brixworth Country Park near Northampton, the course traverses beautiful countryside, including canal towpaths and 14 vil..

The 50 Mile Grand Slam 2026, organized by Centurion Running, is a series of four challenging 50-mile ultramarathons held across iconic UK trails. The event includes the South Downs Way 50, North Downs Way 50, Chiltern Wonderland 50, and Wendover Woods 50, taking place between April and November 2026..

The Battle of the Brampton Valley Way is a unique ultra running event held in Leicestershire and Northamptonshire, featuring a 28-mile (45km) out-and-back course along the flat, traffic-free Brampton Valley Way. Runners choose to start from either Market Harborough or Northampton, representing their..

The Nene Valley Races - Kings Cliffe 10K is a friendly and scenic trail running event held in the beautiful Nene Valley countryside, starting and finishing at KC Active in Kings Cliffe, Northamptonshire. The circular 10K course features easy tracks, green fields, farm paths, and disused railway line..

The Wild Horse South Wales 200 is an epic 200-mile ultramarathon traversing the scenic trails and mountains of South Wales. The course begins in Chepstow and finishes at Worm’s Head, following iconic routes such as Offa’s Dyke, the Beacons Way, the Heart of Wales Line, and the Wales Coast Path. This..

The Windsor 50 Ultra Challenge, formerly known as the Easter 50, is a premier UK trail running and trekking event held at Windsor Racecourse. Scheduled for April 18, 2026, it offers three looped distance options: a 50 km ultra, a historic 25 km, and a 10 km challenge. Participants traverse scenic ro..

Cymoedd Sir Fynwy is a challenging mountain walking event organized by South Wales LDWA, held in Abergavenny, Wales. It features three distance options: 50 miles, 30 miles, and a new 20-mile route, all exploring the rugged terrain of the Black Mountains and the World Heritage Site of the Forgotten L..

The Chiltern Ridge Classic 50K is an iconic ultra marathon held in the Chiltern Hills, UK, featuring a challenging 51 km trail with 996m of elevation gain. The race starts at historic Berkhamsted Castle and finishes at Hampden Meadow in Wendover, following scenic ridgeline trails through Ashridge Es..

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The Spring Trail Series by Ultra X is a trail running event held at the Cowdray Estate in Surrey, within the scenic South Downs National Park. The series features five race distances: 12km, 25km, 50km, 50 miles, and 110km, all starting and finishing at the same location near Cowdray Farm Shop. The c..

The Thames Ring 250 is a challenging 250-mile (approximately 256 miles) trail ultramarathon starting and finishing in Streatley-on-Thames, UK. The race follows an anti-clockwise loop along the Thames, the Grand Union Canal, and the Oxford Canal, primarily on flat canal and riverside paths. Despite t..