Andes.
Formation began roughly 200 million years ago, with the modern range's major uplift occurring within the last 25 million years.
A landscape with a history.
Formed where the oceanic Nazca Plate subducts beneath the continental South American Plate. That subduction both compresses and folds the continental crust and feeds the magma supply for the range's many active stratovolcanoes — making the Andes a direct, large-scale example of the connection between mountain-building and volcanism described on both topic pages.
What makes it remarkable
The longest continental mountain range on Earth, and home to some of the highest volcanoes in the world.
Another skyline. Another story.
Himalayas
Began forming approximately 50 million years ago; still actively rising today.
Rocky Mountains
Primary formation (the Laramide orogeny) occurred roughly 80–55 million years ago.
Appalachian Mountains
Began forming approximately 480 million years ago.