of Santa Cruz de la Sierra, in Bolivia. In addition, there is the Pan-American Highway, which crosses Argentina and the Andean countries from north to south, although some stretches are unfinished. Two areas of greater density occur in the railway sector: the platinum network, which develops around the Platine region, largely belonging to Argentina, with more than 45,000 km in length; And the Southeast Brazil network, which mainly serves the state of São Paulo, state of Rio de Janeiro and Minas Gerais. Brazil and Argentina also stand out in the road sector. In addition to the modern roads that extend through northern Argentina and south-east and south of Brazil, a vast road complex aims to link Brasília, the federal capital, to the South, Southeast, Northeast and Northern regions of Brazil. South America has one of the largest bays of navigable inland waterways in the world, represented mainly by the Amazon basin, the Platine basin, the São Francisco and the Orinoco basins, Brazil having about 54,000 km navigable, while Argentina has 6,500 km and Venezuela, 1,200 km. The two main merchant fleets also belong to Brazil and Argentina. The following are those of Chile, Venezuela, Peru and Colombia. The largest ports in commercial movement are those of Buenos Aires, Santos, Rio de Janeiro, Bahía Blanca, Rosario, Valparaíso, Recife, Salvador, Montevideo, Paranaguá, Rio Grande, Fortaleza, Belém and Maracaibo. In South America, commercial aviation has a magnificent expansion field, which has one of the largest traffic density lines in the world, Rio de Janeiro–São Paulo, and large airports, such as Congonhas, São Paulo–Guarulhos International and Viracopos (São Paulo), Rio de Janeiro International and Santos Dumont (Rio de Janeiro), El Dorado (Bogotá), Ezeiza (Buenos Aires), Tancredo Neves International Airport (Belo Horizonte), Curitiba International Airport (Curitiba), Brasilia, Caracas, Montevideo, Lima, Viru Viru International Airport (Santa Cruz de la Sierra), Recife, Salvador, Salgado Filho International Airport (Porto Alegre), Fortaleza, Manaus and Belém. The main public transport in major cities is the bus. Many cities also have a diverse system of metro and subway trains, the first of which was the Buenos Aires subte, opened 1913. The Santiago subway is the largest network in South America, with 103 km, while the São Paulo subway is the largest in transportation, with more than 4.6 million passengers per day and was voted the best in the Americas. Rio de Janeiro installed the first railroad of the continent in 1854.