Not only the largest country in South America and the fifth largest country in the world but Brazil is also one of the world's most populated countries with a population of over 187 million.  With a coastline of over 7,491 kilometres (4,655 mi), the majority of which lies along the Atlantic Ocean, Brazil is bordered on the north by Venezuela, Suriname, Guyana and the French Guiana; on the northwest by Colombia; on the west by Bolivia and Peru; on the southwest by Argentina and Paraguay; and on the south by Uruguay. Brazil occupies much of South America's interior region making Brazil one of the most geographically and biologically diverse regions in the world.

Brazil's most famous geographical area is the Amazon Basin, however the topography of the country also includes grassland, mountains, highlands, and plains.  The main upland area occupies most of the southern half of the country. The north-western parts of the plateau consist of broad, rolling terrain broken by low, rounded hills. The south-eastern section is more rugged, with a complex mass of ridges and mountain ranges reaching elevations of up to 1,200 metres (3,900 ft). These ranges include the Mantiqueira Mountains, the Espinhaço Mountains, and the Serra do Mar. In the north, the Guiana Highlands form a major drainage divide, separating rivers that flow south into the Amazon Basin from rivers that empty into the Orinoco river system, in Venezuela, to the north. 

Brazil has a dense and complex system of rivers, one of the world's most extensive, with eight major drainage basins, all of which drain into the Atlantic Ocean. Major rivers include the Amazon, the largest river in terms of volume of water, and the second-longest in the world; the Parana and its major tributary, the Iguaçu River, where the Iguaçu Falls are located; the Negro, São Francisco, Xingu, Madeira and the Tapajos rivers.