Trail du Caillou begins in Sebourg, located in the Valenciennois region of Hauts-de-France, on the first weekend of February. This series offers trail running and walking events, featuring a 13 km walk and three races: the 13 km La Sabine, the 23 km Trail qui Se Bourg, and the 30 km Trail du Caillou. The latter requires participants to carry sufficient water and energy food for a partially self-supported effort.
The courses are set in the border region near Sebourg, crossing locations like the Bettrechies quarry, Mormal forest, Hogneau valley, and the Belgian communes of Honnelles. Participants will also go through Parc du Caillou and villages such as Sebourg, Bellignies, Bettrechies, and Gussignies. The event is organized by local ultra-trail runners from Hauts-de-France, who have competed in events ranging from desert races to Mont Blanc, La Diagonale des Fous, Madeira, and Gran Canaria. They established this event partly because the region had a scarcity of trail races early in the year.