Wikipedia
The Sertão (, " outback" or " backcountry") is one of the four sub-regions of the northeast of Brazil.
Originally the term referred to the vast hinterlands of Asia and South America that Lusitanian explorers encountered. In Brazil it referred to backlands away from the Atlantic coastal regions where the Portuguese first settled in South America in the early sixteenth century. A Brazilian historian once referred to colonial life in Brazil as a "civilization of crabs", as most settlers clung to the shoreline, with few trying to make inroads into the sertão. In modern terms, "sertão" refers to the semi-arid region in Northeastern Brazil comprising parts of the states of Alagoas, Bahia, Pernambuco, Paraíba, Rio Grande do Norte, Ceará, Maranhão, Piauí, and parts of northern Minas Gerais. The term Vaqueiro is similar to the generic use of " cowboy" in the United States.
Geographically, the sertão consists mainly of low uplands that form part of the Brazilian Highlands. Most parts of the sertão are between 200 and 500 meters above sea level, with higher elevations found on the eastern edge in the Planalto da Borborema, where it merges into a sub-humid region known as agreste, in the Serra da Ibiapaba in western Ceará and in the Serro do Periquito of central Pernambuco. In the north, the sertão extends to the northern coastal plains of Rio Grande do Norte state, whilst in the south it fades out in the northern fringe of Minas Gerais.
Two major rivers cross the sertão, the Rio Jaguaribe and the Rio Piranhas further east. Apart from the Rio São Francisco which originates outside the region, other rivers dry out after the rainy periods end.