Established on 200ha of marshland, dunes and reedbeds, between the estuaries of the Authie and the Somme, the Marquenterre Park is the land part of the Baie de Somme Nature Reserve. This well-preserved natural universe, only accessible on foot, is a haven for some 300 species of birds and a port of call for numerous migrators. Three waymarked itineraries with information panels riddle the site.