London South Tough Mudder 15K - Sunday September 20th 2026

Tough Mudder London South is held at Holmbush Estate in West Sussex each September, utilizing its wooded terrain. Participants can select a 5K route with over 12 obstacles or a 15K course with over 20 obstacles. The event does not employ timing chips or award speed-based prizes, encouraging participants to assist teammates and fellow runners rather than compete against them. The course incorporates steep hills, natural mudslides, and challenging climbs to test endurance. Notable obstacles include Augustus Gloop, where participants ascend a tube while sprayed by a fire hose, and the net-climbing Mudderhorn. Those who complete the course receive a medal, shirt, and orange headband. A Kids Adventure event is available for ages 4-14, and participants can run for the charity Wooden Spoon with a minimum sponsorship of £250.