Intrail-Muros is a 12 km night urban trail inside the fortified Intra-Muros quarter of Saint-Malo, on Brittany’s coast. It is run in February, in cold winter conditions, with starts and finishes based at Saint-Malo Le Naye Salle omnisport. The event has been held in Saint-Malo since 2015 and now draws more than 5,000 runners across its formats. The individual race has no official timing, so it leans more toward shared night running than a pure chase for splits.
The route sends runners through the streets of the old walled city and nearby areas, using Saint-Malo’s Corsair City setting as part of the experience. There is an individual entry capped at 2,850 runners, plus a company challenge for teams of four to six, with space for 400 teams. Runners must be at least 16, carry required gear, and get their only official aid station at the finish. The race is pitched as festive as well as nocturnal, and past editions have filled the old city with thousands of headlamps and local support after dark.