Concept map on Brazil (geography). Brazil is the largest and most populous state in South America. It borders numerous countries: Colombia, Peru, Venezuela, Guyana, Suriname, French Guiana, Bolivia, Paraguay, Uruguay and Argentina. It is a federal presidential republic. The territory comprises vast natural regions: the Amazonian lowlands, with the immense alluvial plain of the Amazon River and the large Amazon rainforest, and relief areas such as the Guiana Shield, where Pico da Neblina is located, and the highlands of Mato Grosso and Brazil. The main rivers are the Amazon River, the ParanĂ¡ and the Paraguay. The climate varies: tropical in the Amazon basin, temperate on the coast and drier in the highlands. The economy is based on agriculture, raw materials, energy and tourism.