The Trail du Château de Pierrefonds begins on the esplanade of the Château de Pierrefonds, a 15th-century fortress in the Oise department of Hauts-de-France, near Paris. Organized by OK Aventure, this January trail race offers two running distances, 13 km and 27 km, alongside a walking option for those who prefer to enjoy the scenery without the competitive aspect. The longer route includes 600 meters of elevation gain, indicating it is not a flat course, despite its highest point reaching only 146 meters.
The course winds through the Compiègne forest surrounding Pierrefonds, combining woodland paths with the village and its castle. The winter timing is significant, with participants advised to wear hats and gloves, contributing to the event's cold-weather, early-season atmosphere. The château also has a connection to film history, having been a filming location for Les Visiteurs. Beyond the race, OK Aventure has supported healthcare staff through this event, with donations to the Compiègne Noyon hospital center and gift boxes for massage therapy valued at 1000 euros.