Rio de Janeiro
Rio has more people living in slums than any other city in Brazil, according to the 2010 Census. More than 1,500,000 people live in its 763 favelas, 22% of Rio's total population. São Paulo, the largest city in Brazil, has more favelas (1,020) in sheer numbers, but proportionally has fewer people living in favelas than Rio.
History of Rio de Janeiro
At the beginning of the 18th century, Brazil began to engage in gold and diamond mining, which brought about remarkable changes in the colony's economy and stimulated a great migration from Europe, thereby increasing the number of people of European ancestry. The former village became a town of 24,000 in 1749. When the colonial capital was transferred from Salvador, Bahia to Rio de Janeiro in 1763, the town expanded farther, far beyond its walls. The remains of the monumental Roman-style aqueduct Arcos da Lapa (Lapa Arches) built at this time still stand in the city.