the aquitaine region was the third largest region of metropolitan france, after midi-pyrénées and rhône-alpes. its area was . it bordered with three french regions: poitou-charentes to the north, limousin to the northeast and midi-pyrénées to the east. to the south is spain (aragon and navarre) and to the west the atlantic ocean. the coast along the atlantic ocean, part of the bay of biscay, is called the côte d'argent ("silver coast").