Trail Urbain Cosséen is a night urban trail race in Cossé-le-Vivien, France, offering 8 km or 16 km distances. A headlamp is required as the race takes participants through the town after dark, deviating from a typical daytime road course. The 8 km race consists of a single loop, while the 16 km race comprises two loops. The entire route is marked by the organizers from Avant-Garde Cossé-le-Vivien Athlétisme.
The course navigates the streets of Cossé-le-Vivien and includes passage through some buildings. The terrain is primarily road with potential path sections. Aid stations are provided along the circuit, and participants receive refreshments and showers at the finish. The inaugural race saw a local victory: Maël Ferron, a triathlete from Cossé-le-Vivien, secured the win in the 16 km race by pulling away in the final four kilometers. Théo Passelande won the 8 km race, having followed the UC Sud 53 triathletes.