A loop of over 120 kilometers begins in Miramas, encircling the Etang de Berre, a large saltwater lagoon west of Marseille. The Grand Tour de l’Etang-de-Berre is an endurance walk, not a timed race; the objective is to finish and gain finisher status. Participants travel in semi-autonomy, day and night, covering approximately 2,000 meters of elevation gain on the full route. The Bouches-du-Rhône departmental hiking committee organizes the event, targeting individuals who appreciate extended hikes and self-directed challenges.
The course largely follows the GR 2013 trail. It can be completed solo, as a two-person relay covering the full distance, or as a shorter half tour starting from Marignane, approximately 54 to 55 kilometers. The relay divides the full distance into legs of roughly 70 and 54 kilometers. Aid stations are positioned 20 to 32 kilometers apart, with opening hours adjusted to walking pace, accommodating runners while maintaining a walker-centric rhythm. The lagoon is Europe's second-largest saltwater lagoon, with its shores hosting abundant flora and fauna, including over 250 bird species, both resident and migratory. Participants must carry necessary items like water, food, a charged phone, a headlamp, and a reflective vest.