|Primary inflows||Agüera, Asón, Bidasoa , Cares-Deva, Eo, Escudo, Miera, Nalón, Nansa, Navia, Pas, Pisueña, Saja-Besaya, Sella, Piles|
|Basin countries||Spain, France|
|Max. length||800 km (497 mi)|
|Max. depth||2,789 m (9,150 ft)|
The Cantabrian Sea[a] is the term used mostly in Spain to describe the southern part of the Bay of Biscay. It is the coastal sea of the Atlantic Ocean that washes the northern coast of Spain and the southwest side of the Atlantic coast of France; it represents the south area of the Bay of Biscay. It extends from the cape Estaca de Bares in the province of A Coruña, to the mouth of the Adour river, near the city of Bayonne on the coast of the department of Pyrenees Atlantiques in French Basque Country.