Chiltern Hills 100K

Discover the curated beauty of the Chiltern Hills on the Chiltern Hills 100K ultra marathon, starting at 7:00 AM on Saturday, 9th May 2026. This UTMB World Series Index Race offers an 18-hour journey through quintessential English countryside, following a meticulously planned anticlockwise loop from Chesham. Traverse iconic landmarks like the Ashridge Estate, Coombe Hill, and Whiteleaf, with significant stretches on the ancient Ridgeway National Trail. As a fully marked and professionally supported event, it provides the perfect balance of challenging navigation and accessible ultra-running, complete with GPS tracking and well-stocked aid stations. Perfect for runners seeking a major qualifying race or a classic 100K personal achievement, this event delivers a world-class experience on beloved local trails. Secure your spot for a premium ultra that showcases the very best of the Chilterns.