Six major mountain ranges exist in the world, with a host of minor attached chains and some solitary mountains. Three of the major mountain ranges are located in the Western Hemisphere. Mountain ranges are created by Earth's tectonic plates pressing against one another.
The longest mountain range is the Andes, located along the western coast of South America. In North America, the two major chains are the Rockies and the Appalachians, located in the west and east respectively. Also in the west are the Cascades and Sierras.
The Eastern Hemisphere is host to the Alps, which mostly isolate Switzerland; the Urals, which serve as a natural border between Europe and Asia; and the Himalayas, separating the Indian subcontinent from the rest of Asia.