Chiltern Hills 100K

Chesham, United Kingdom • 2 Oct 2027

Chiltern Hills 100K

The Chiltern Hills 100K is a 100K ultra marathon held on 2 October 2027. The route is an anticlockwise loop that starts and finishes in Chesham, based at the Chesham Guides Headquarters in Lowndes Park, HP5 1HX. The course passes notable Chiltern landmarks including the Ashridge Estate, Ivinghoe Beacon, Coombe Hill, Whiteleaf Hill, Bledlow Ridge and Great Hampden, and returns to Chesham.

The route covers approximately 100K with over 1800m of ascent. Navigation is fully marked with arrows and ribbons and open GPS tracking is provided. There are six checkpoints at roughly 14K, 28K, 41.4K, 57.8K, 75.3K and 88K; a drop bag service is available at the 41.4K checkpoint. The event is limited to 250 runners, has a 19 hour time allowance and requires runners to be at least 20 years old. The race is licensed by the Trail Running Association and held under UKA rules and is an UTMB World Series index race.

Aid stations supply water, electrolyte drink, gels, chews, snacks, sandwiches and fresh fruit; hot drinks are available at selected locations. All runners must carry mandatory kit for the whole event, including a mobile phone, route GPX, minimum 0.5L hydration, waterproof jacket, additional layers, head torch and spare battery, basic first aid, a reusable cup and payment for emergencies. Event services include chip timing with live results, medical support, event photos and a finishers medal and t-shirt. Visit the organization's website for the most recent information.

Race information

100 km
100k
Visit the organization's website for the most recent information.
Trail runs nearby

An evening trail event at Wendover Woods on 18 July 2026 raising funds for the Chilterns Neuro Centre. It offers 10K, 5K and an accessible 1.5K with marked routes, chip timing and on-course support.

A chip timed 10 km race around Highfield Park and the Alban Way in St Albans on 19 July 2026. The event village features a free family fun run, kids zone, live music and a charity partnership with Alzheimer’s Research UK.

A trail half marathon and 10k on Wimbledon Common on 19 July 2026, with marked miles, marshals and a 3.5 hour cut off. RunThrough provides an event village, finish-line goodies and an optional event t-shirt.

Seven hour Time Challenge along the River Thames with distances from 3 km up to 50 km, fully signed laps, medals and distance pins, aid stations and vegan goody bags.

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