<P> The geography of South America contains many diverse regions and climates . Geographically, South America is generally considered a continent forming the southern portion of the American landmass, south and east of the Panama--Colombia border by most authorities, or south and east of the Panama Canal by some . South and North America)) are sometimes considered a single continent or supercontinent, while constituent regions are infrequently considered subcontinents . </P> <P> South America became attached to North America only recently (geologically speaking) with the formation of the Isthmus of Panama some 3 million years ago, which resulted in the Great American Interchange . The Andes, likewise a comparatively young and seismically restless mountain range, runs down the western edge of the continent; the land to the east of the northern Andes is largely tropical rain forest, the vast Amazon River basin . The continent also contains drier regions such as eastern Patagonia and the extremely arid Atacama desert . </P> <P> The South American continent also includes various islands, most of which belong to countries on the continent . The Caribbean territories are grouped with North America . The South American nations that border the Caribbean Sea--including Colombia, Venezuela, Guyana, Suriname, and French Guiana--are also known as Caribbean South America . </P>

Tropical rain forest that covers most of the northern half of south america
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