Final answer:
The Bay of Biscay is the bay that forms the Atlantic coast of Spain, bordered by the northern coast of Spain and the western coast of France, extending to the Strait of Gibraltar.
Step-by-step explanation:
The bay that forms the Atlantic coast of Spain is the Bay of Biscay. This bay is situated in the northeastern part of the Atlantic Ocean, bordered by the northern coast of Spain and the western coast of France. It is known for its rough seas and has historically been an important area for shipping and fishing.
The southern boundary of the Bay of Biscay extends to the northern coast of Spain, where the Spanish shoreline then continues southwest to the Strait of Gibraltar, which serves as a natural divider between the Atlantic Ocean and the Mediterranean Sea, and separates Europe from Africa.
The proximity of Spain to North Africa across the narrow strait has influenced the region's history, culture, and demographic movements.