Capital of the state of Amazonas, Manaus has been the export hub of the Amazon River region since the late 19th century, but its economy really took off when it was designated a duty-free zone in the 1960s. Today, with a population almost 2 million, the city is a key player in Brazilian tourism: It’s the gateway to the Amazon rainforest, embarkation port for many Amazon river cruises, and home to the only international airport on the Brazilian side of this mighty river.