From the Super Mario Wiki
South America is a continent located on Earth which consists of countries such as Ecuador, Suriname, Brazil, Guiana, French Guiana, Colombia, Peru, Argentina, and Chile. It is well known for its tropical climate and rainforests.
South America appeared in an episode of The Adventures of Super Mario Bros. 3, "7 Continents for 7 Koopas". When Bowser tried to conquer the entire Real World, he put Hop Koopa under control of South America. Hop used his Magic Wand to turn the Amazon Rainforest into a giant parking lot. However, Mario later restored the jungle to its natural form by using Hop's own Magic Wand.