Which More mountainous eastern or western south America?

Western South America is more mountainous than Eastern South America.

The Andes mountain range is located along the western coast of South America and is the longest continental mountain range in the world, stretching over 7,000 kilometers. The mountain range is formed by the collision of the Nazca Plate and South American Plate, and includes many high peaks, including Aconcagua, the highest mountain in the Americas.

Eastern South America, on the other hand, is relatively flat, with the exception of the Guiana Highlands in Venezuela, Guyana, and Suriname, and the Brazilian Highlands in Brazil. These regions are characterized by rolling hills and plateaus, but do not reach the same elevations as the Andes.