This manuscript map shows the city of Rio de Janeiro spread along the shores of Guanabara Bay. The map, which is the work of José Correia Rangel de Bulhões, emphasizes the defenses of the city and the port. Rio de Janeiro displaced Salvador as Brazil’s most important port after gold and diamonds were discovered in nearby Minas Gerais province in 1720. The city became the colonial capital in 1763. Brazil -- History -- Colonial Period, 1500-1822; Guanabara Bay (Brazil)