La Gailhardaise is a night trail race starting in Montgailhard, a medieval town near Foix in Ariège, France, situated by the Ariège Pyrenees Natural Park. Typically held in early November, it begins in the late afternoon, sending participants into the forest as dusk settles. The primary event covers approximately 26 to 28.7 km with around 1,320 metres of elevation gain, available as a solo effort or a two-person relay.
The course is predominantly on trails, crossing hilly forest terrain within and near the Pech and Foix state forests. Relay divisions divide the race into two sections, with specified legs like 11.1 km and 17.6 km, or circuits of 13.1 km and 15.7 km. Sport Nature Montgailhard is the organizer, and the event adopts a medieval, mock-battle theme, where participants exchange a sword for a relay baton. The post-race activities include showers, meals available by reservation, and a dance.