The mountain range that forms the northeastern border of Spain is the Pyrenees. The Pyrenees stretch over 400 kilometers between the regions of Navarre, Aragon, and Catalonia in Spain, acting as a natural border between Spain and France. This range extends from the Mediterranean Sea in the east to the Atlantic Ocean's Bay of Biscay in the west, and it forms a significant natural barrier dividing the Iberian Peninsula from the rest of Europe.
