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.
Recife
The Recife metropolitan area is the 5th most populous of Brazil, after São Paulo, Rio de Janeiro, Belo Horizonte and Porto Alegre, and the first in the Northeast region. The most populous neighborhoods of Recife in 2008 were Boa Viagem (100,388), Casa Amarela (69,134), and Várzea (64,512).