Manaus's Centro is a tight grid of late-nineteenth and early-twentieth-century buildings between the Teatro Amazonas, the cathedral, and the riverfront. Most of the city's historic landmarks are here: the floating port, the cast-iron Mercado, the Palácio Rio Negro, the Largo de São Sebastião with its wave paving. The streets are dense, often grimy, sometimes raucous, and full of commerce — wholesalers of hammocks, shoes, fishing tackle, knock-off electronics from the free-trade zone.
It is the obvious place to base yourself for the historic sights, and easily walkable in the cooler hours. After dark the area around the Teatro stays busy with bars and restaurants; the streets immediately around the port should be treated with sensible caution at night.