A beautiful but challenging 50km trail ultra through the heart of the Chiltern countryside, based at Stonor Park near Henley-on-Thames. The route takes two different 25km loops covering approximately 4,000ft of climb through picturesque villages and ancient woodland. Runners are supported by 5 well-stocked aid stations, a dedicated medical team, and hot food at the finish included in the entry fee. Race held under full UK Athletics Permit. Field size: 600 starters.