A 183 km (114 mile) mountain ultramarathon in the Lake District National Park starting and finishing in Coniston, with approximately 7,000 m of ascent. The route links thirteen Lakeland valleys via high passes, valley trails and sections of rough mountain terrain typical of the central fells. Elevation is gained through sustained climbs and long descents between valleys rather than short rolling hills. Underfoot conditions vary from stone-pitched paths and rocky trail to rough ground on higher sections, with extended exposed terrain on passes. The course is partially marked with checkpoints and aid stations positioned at intervals.

• Other races at the same event:
7 Valleys 110K (110 km)
5 Valleys 50K (58 km)
2 Valleys Trail (approx. 22 km)