a range of mountains between France and Spain, which goes from the Bay of Biscay to the Mediterranean Sea. Mountain range, southwestern Europe. It extends 270 mi (430 km) from the Mediterranean Sea to the Bay of Biscay on the Atlantic Ocean. The Pyrenees form a high wall between France and Spain; generally, the crest of the range marks the boundary between the two countries. The tiny, autonomous principality of Andorra lies among the range's peaks. The highest point is Aneto Peak, elevation 11,169 ft (3,404 m). There are few passes through the mountains. The pass at Roncesvalles was made famous in the 12th-century La Chanson de Roland, based on the 778 Battle of Roncesvalles (Roncevaux)