2. Caucasus Mountains: The Caucasus Mountains form a natural border between Europe and Asia. They stretch across Georgia, Armenia, Azerbaijan, and parts of Russia. The highest peak in the Caucasus Mountains is Mount Elbrus, located in Russia, which stands at 5,642 meters (18,510 ft) above sea level, making it the highest mountain in Europe.
3. Pyrenees: The Pyrenees form a natural border between France and Spain. The highest peak in the Pyrenees is Aneto, located in Spain, which stands at 3,404 meters (11,168 ft) above sea level.
4. Apennines: The Apennines are a mountain range forming the backbone of Italy, stretching from north to south. The highest peak in the Apennines is Corno Grande, located in the Gran Sasso massif, which stands at 2,912 meters (9,554 ft) above sea level.