The Course Nature de Laignelet is a trail and nature-running event held in late June in Laignelet, Ille-et-Vilaine, Brittany. Most of the running takes place within the Fougères forest, with minimal road sections. Participants can select from three primary distances: 4.6 km, 15.3 km, and 33.8 km. The 33.8 km race is named Le Défi de l'Oppidum, the 15.3 km race is Le Cordon des Druides, and the 4.6 km race is L'Agnelaise.
The routes feature forest paths, river crossings, and tunnels, making it a woodland trail event rather than a road race. The 15.3 km option attracts the largest number of participants, with over 100 runners in the last edition. The event also offers a 15.2 km Nordic walk, a 5 km discovery race, and free races for children and juniors.