The BioTrail begins in the medieval village of Biot, in the Alpes-Maritimes, leading runners into the Brague valley above the French Riviera. Organized by Biot Running, the event typically offers 12 km and 23 km routes. The shorter route ascends approximately 400 metres, and the longer route ascends about 700 metres. Shorter formats are available for children and juniors, making the event suitable for more than just experienced mountain runners.
The course's unique appeal lies in its access: sections traverse private land on the Plateau des Aspres, usually off-limits. Participants also go through the Volcan de Biot area, with andesite, cinerite, and compacted volcanic ash, which provides exceptional grip even when wet. The Natura 2000-protected plateau features arid, distinctive vegetation, including succulents and cacti, leading locals to nickname it “Petit Mexique.” The route combines forest, open natural terrain, and village sections, offering a varied experience beyond a standard out-and-back trail race.