The Andes Mountains are a continental mountain range that is located on the western coast of South America. They are the longest continental mountain range in the world, spanning over 7,000 kilometers (4,350 miles). The Andes Mountains are also one of the highest continental mountain ranges in the world, with some peaks reaching over 6,000 meters (19,700 feet).

The Andes Mountains are still geologically active, and there are many volcanoes in the region. The Andes Mountains are also home to some of the world's largest copper and gold mines.

The other three mountain ranges listed are all older than the Andes Mountains. The Appalachian Mountains in North America are estimated to be about 480 million years old. The Ural Mountains in Russia are estimated to be about 300 million years old. The Atlas Mountains in Africa are estimated to be about 180 million years old.