Brazil covers almost half of the South American continent and it is bordered to the north, west and south by all South American countries except Chile and Ecuador; to the east is the Atlantic ocean. The country is topographically relatively flat; at no point do the highlands exceed 3,000m (10,000ft). Over 60% of the country is a plateau; the remainder consists of plains. The River Plate Basin (the confluence of the Paraná and Uruguay rivers, both of which have their sources in Brazil) in the far south is more varied, higher and less heavily forested.
North of the Amazon are the Guiana Highlands, partly forested, partly stony desert. The Brazilian Highlands of the interior, between the Amazon and the rivers of the south, form a vast tableland, the Mato Grosso, from which rise mountains in the southwest that form a steep protective barrier from the coast called the Great Escarpment, breached by deeply cut river beds. The population is concentrated in the southeastern states of Minas Gerais, Rio de Janeiro and São Paulo. The city of São Paulo has a population of over 12 million, while over 7 million people live in the city of Rio de Janeiro.