Manaus is located in the middle of the Amazon rain forest, and access to the city is primarily by boat or airplane. This isolation helped preserve both the natural environment as well as the culture of the city. The culture of Manaus, more than in any other urban area of Brazil, preserves the habits of Native Brazilian tribes. The city is the main access point for visiting the fauna and flora of the Brazilian Amazon. Few places in the world afford such a variety of plants, birds, insects, and fishes.
Manaus is also a duty-free zone, which caused/encouraged high development in the region. It also came along with a free trade zone around 1967. It also has a free economic zone, which is the Industrial Park of Manaus, which is the city's main industrial engine.
Sorry I don't know if this answers your question at all but I hope it can help you in some way. have a good day :)
