Trail des Ajoncs takes place in April in Malguénac, Morbihan, starting from the Saint Neot multi-purpose hall. Runners can choose from four distances: 45 km, 25 km, 15 km, or 9 km. The 45 km Grand Trail des Ajoncs involves approximately 1,100 m of elevation gain, the 25 km about 700 m, the 15 km about 400 m, and the 9 km Trail de la Cascade offers about 200 m of climbing. Aid stations are provided during the races, and participants have access to showers and a buffet afterward.
The routes are predominantly off-road, with about 98% on trails, designed by trail runners for trail runners. The courses feature singletrack, secluded paths around Malguénac, natural sites, and challenging climbs that differentiate the shorter races from casual runs. The event also features children's races of 600 m, 1600 m, or 2000 m, and a 2900 m race for teenagers. Organized by the Mairie de Malguénac, it is part of the Triskell Challenge. One euro from each registration is donated to the Roz’AS association. Post-race activities include music from a band and DJ, along with food trucks at the Salle Résonance.