Thank you for your interest in the Chiltern 50 Ultra Challenge, unfortunately sign ups are now closed. If you are interested in taking on an alternative Ultra Challenge please see our Ultra Challenge events, or view our full events calendar for more options.
A 50km looped challenge in some of the Chilterns finest countryside, with historic trails, rolling hills, nature reserves, with fantastic views. Join up to 2,000 adventurers and take it on at your pace as a walk, jog, or run – and fundraise for Acorns!
A basecamp in Henley-on-Thames, a route with real variety, some wonderful scenery and easily accessible from London. Sign up as an individual or as a team; you’ll get full support all the way, plenty of food and drink, optional camping and transfers, a special medal, t shirt and celebration finish. With 25km and 10km options also available, there’s a Chilterns Challenge for everyone!
Push yourself further in 2026, take on an Ultra Challenge – the UK’s number one series of treks and trail challenges!
