Saint-Valery-sur-Somme, commune in the Somme department, is a seaport and resort on the south bank of the River Somme estuary. T…Saint-Valery-sur-Somme, commune in the Somme department, is a seaport and resort on the south bank of the River Somme estuary. The town's medieval character and ramparts, its Gothic church and long waterside boardwalk, make it a popular tourist destination.