Natura Carolo is a forest trail race held in Charleville-Mézières, located in the Ardennes region of northern France, with events scheduled for early March. The race begins in the city, quickly leading participants into the surrounding woodland, offering a natural setting within the local "Carolo" area. The event has featured various distances, ranging from approximately 9.5 km to a marathon, with recent course details indicating 14 km, 26 km, and 42 km options.
The routes are predominantly set within forests, involving minimal road crossings based on the chosen distance. The shorter race is designed for participants seeking a less demanding run, while the intermediate distances provide a genuine trail running challenge. The 42 km course includes around 1,600 meters of elevation gain. This event is relatively new, with its sixth edition announced, and is based at the Rouget de Lisle gymnasium in Charleville-Mézières.