Chiltern Hills 100K

Chiltern Hills 100K

The Chiltern Hills 100K is a trail ultramarathon held on 9 May 2026 and based at Chesham Guides Headquarters in Lowndes Park, Chesham, Buckinghamshire. The route is an anticlockwise loop of roughly 100 kilometres with over 1800 metres of ascent, following sections of The Ridgeway and passing landmarks such as the Ashridge Estate, Ivinghoe Beacon, Coombe Hill, Whiteleaf Hill, Bledlow Ridge, Great Hampden and Great Missenden.

The course is fully marked and the event uses open GPS tracking. Navigation requirements include carrying a GPX route on a watch or phone and a printed map provided at registration. There are six main checkpoints at approximately 14K (Hastoe), 28K (Little Gaddesden), 41.4K (Hastoe), 57.8K (Whiteleaf Hill), 75.3K (Bledlow Ridge Village Hall) and 88K (Little Hampden). Aid stations supply water, soft drinks, electrolyte drink mixes, gels and chews, snacks, pre-made sandwiches, flapjacks, fresh fruit and hot drinks at later checkpoints.

The event is licensed by the Trail Running Association and held under UKA rules. Entries are limited to 250 runners and the minimum age is 20. Time allowed for completion is 18 hours. Included for entrants are chip timing with live results, GPS tracking, a drop bag at Hastoe, medical support, event photos and a post-race meal. Required kit includes a mobile phone, route GPX, refillable hydration (minimum 0.5L), waterproof jacket, warm layers, head torch with spare battery, basic first aid and a reusable cup. Visit the organization's website for the most recent information.