Intrail-Muros is a night urban trail race in Saint-Malo, covering 12 km through the fortified Intra-Muros district. The primary individual race is untimed, limited to 2,850 participants, and begins and ends at the Village Course near the Le Naye sports hall. A corporate challenge covers the same distance, featuring 400 teams of four to six runners with official timing. Additionally, a Kids Trail, ranging from 1.5 to 3 km, offers a reward to every child.
The route's character stems from running within the old corsair city after dark, with ramparts and narrow streets illuminated by thousands of headlamps and small lights. For its eleventh edition, the event attracted 5,700 runners and local spectators, prompting Ouest France to describe it as “a race icon” in Saint-Malo. Registration is managed via KLIKEGO. Participants must be at least 16 years old for the 12 km races. A mandatory kit is required, and the sole aid station is located at the finish line.