The Ural Mountains
The Ural Mountains run from north to south through Central Asia, separating Europe from Asia. Like the Appalachian Mountains, the Ural Mountains formed about 300 million years ago, near the end of the Carboniferous period, when the first reptiles were evolving. This was when the tectonic plates began to form the supercontinent of Pangaea. When the western Siberia plate smashed into the Baltica and North America plate, that pushed up the land to make the Ural mountains, and formed the supercontinent of Laurasia. But the Ural Mountains are not as eroded as the Appalachians; some of them still have glaciers at their tops all year round.
The Ural mountains, together with the Appalachians, are among the oldest mountains in the world. They are far older than the Alps, the Himalayas, the Rockies, or even the Andes, which are the next oldest major mountains.