After a winding 245-km journey from its source near Saint-Quentin, the River Somme finally empties into this broad, sheltered bay where William the Conquerer took refuge from the elements on his way to invade England. A large natural preserve on the northern tip of the estuary surrounds the Parc Ornothologique de Marquenterre, a tract of dunes, wetlands and pine woods which offers sanctuary to a spectacular variety of wildfowl.

The fishing villages of Le Crotoy and Saint-Valéry-sur-Somme face each other across the bay, linked by an attractive steam train ride on the Chemin de Fer de la Baie de Somme in summer. The train chugs on to the coast at Cayeux-sur-Mer.

Saint-Valéry is a charming base for exploring the area, a particularly pretty spot with its fishermen’s cottages, tree-lined promenade, and 17thC Haute Ville. Local attractions include the Maison de la Baie de Somme Museum with exhibits on the local landscape and a large collection of stuffed and wooden carved birds.