The Pyrenees mountain range forms a natural high-altitude border between France and Spain, effectively isolating the Iberian Peninsula from the rest of continental Europe. Stretching about 430 kilometers from the Bay of Biscay to the Mediterranean Sea, the range also completely encompasses the tiny microstate of Andorra. The mountains were formed by the collision of the Iberian landmass with the European plate millions of years ago. Aneto is the highest peak at 3,404 meters. The Pyrenees are known for their distinct Basque and Catalan cultures, as well as unique biodiversity, including the endangered Pyrenean desman and the bearded vulture. Unlike the Alps, the Pyrenees have fewer large glaciers and more 'cirques'—amphitheater-like valleys carved by ancient ice. They are a popular destination for hikers, skiers, and those seeking the thermal springs located throughout the range.