The northern part of Brazil is dominated by the basin of the Amazon River and its many tributaries, which occupies two-fifths of the country. The Amazon Basin itself occupies 7,049,975 sq km (2,722,000 sq mi), or about 40% of South America's total area. The Amazon River (Rio Amazonas) is, at 6,436 km (4,000 mi), the world's second-longest river after the Nile, although the Amazon ranks first in volume of water carried; rising in the Peruvian Andes, the Amazon eventually empties into the Atlantic Ocean at an average rate of about 198,000 cu m (7 million cu ft) per second. The Amazon lowlands east of the Andes constitute the world's largest tropical rain forest. In the northernmost part of the Amazon Basin lies a series of mountain ranges, known as the Guiana Highlands, where Brazil's highest mountain, Pico da Neblina (3,014 m/9,888 ft), is located. South of the Amazon Basin is a large plateau called the Brazilian Highlands, ranging in elevation from 300 to 910 m (1,000 to 3,000 ft) above sea level. From the city of Salvador (Bahia) southward to Pôrto Alegre, the highlands meet the Atlantic Ocean in a steep, wall-like slope, the Great Escarpment, which in southeastern Brazil is surmounted by mountain ranges with elevations from 2,100 to 2,400 m (7,000 to 8,000 ft) above sea level.
The Atlantic coast of Brazil has no real coastal plain, but there are stretches of lowlands along the northeast coast, and there are many baylike indentations, where Brazil's principal cities are located. Along the southwest border is a small portion of the upper Paraguay lowlands. The Paraná, Paraguay, and Uruguay rivers flow through southern Brazil; the São Francisco flows 3,199 km (1,988 mi) through northeastern and central Brazil; and the Tocantins (2,698 km/1,677 mi) empties into the Pará and from there into the Atlantic Ocean at an estuary south of the Amazon proper.