Three Key Cities on the Amazon River: Manaus, Iquitos, Belém

The Amazon's major urban hubs are gateways to the rainforest:

1. Manaus, Brazil: Capital of Amazonas state; largest city in Brazilian Amazon. Confluence of Negro and Solimões rivers. Major port, industrial zone, ecotourism base.
2. Iquitos, Peru: Largest city unreachable by road; deep in Peruvian Amazon. River port, commerce, jungle tour hub.
3. Belém, Brazil: Capital of Pará; gateway at Amazon's Atlantic mouth. Colonial architecture, museums, major port, industry.

These cities anchor the region's economy, research, and tourism.