Constructed in the nineteenth century to stop the incursions of sea water that precluded agriculture in the southern Camargue, the low-lying sea dyke known as the Digue à la Mer stretches across the mouth of the Rhône. Hiking the rough, narrow track along the top is a wonderful wilderness experience, with open water to either side, flamingos and other birds flying overhead, and the wind roaring in your ears.
While the dyke itself is roughly 12km long, connecting trails at either end make it possible to walk the whole way between Saintes-Maries-de-la-Mer and Salin-de-Giraud. The entire 31km route takes around six hours, with no facilities en route, so most visitors content themselves with an out-and-back round-trip from one end or the other. The Phare de Gacholle lighthouse in the middle, open as an information centre on summer weekends, makes an obvious turn-around point.
If you’re coming from Saintes-Maries-de-la-Mer, simply head 1km east of town, staying close to the sea; the trail starts from the Plage de l’Est, where drivers pay an admission fee. Coming from Salin-de-Giraud, you can park beside the Étang de Fangassier at trailheads either 7km west or 13km northwest of town.