Domaine de Certes et Graveyron protects former fishponds, dikes and wetlands on Arcachon Bay, creating one of the area's best places for quiet walking and birdwatching. The landscape is flat, open and shaped by the meeting of human water management and coastal ecology.
It sits away from Arcachon's resort centre, so plan it as a nature excursion around the bay rather than a town sight. Bring binoculars if you have them, and expect wind and exposure on the dike paths.