Geography of South America 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. 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
Continent to the mainland of Australia, excluding Tasmania and New Guinea. Similarly, the "continental United States" refers to the 48 contiguous states and the District of Columbia in central North America and may include Alaska in the northwest of the continent (the two being separated by Canada), while excluding Hawaii, Puerto Rico, and Guam in the oceans. From the perspective of geology or physical geography, "continent" may be extended beyond the confines of continuous dry land to include the shallow, submerged adjacent area (the continental shelf) and the islands on the shelf (continental islands), as they are structurally part of the