High Quality Content by WIKIPEDIA articles! High Quality Content by WIKIPEDIA articles! The Brazilian highlands (Portuguese: Planalto Brasileiro) are an extensive geographical region, covering most of the eastern, southern and central portions of Brazil, in all approximately half of the country's land area, or some 4,000,000 km² (1,544,000 sq mi). In addition, the vast majority of Brazil's population (186,112,794 2004 est.) lives in the highlands or on the narrow coastal region immediately adjacent to it. Ancient basaltic lava flows gave birth to much of the region. However, the time of dramatic geophysical activity is long past, as there is now no seismic or volcanic activity. Erosion has also played a large part in shaping the Highlands, forming extensive sedimentary deposits and wearing down the mountains.