I found this article about a fire in one of Sao Paulo's favelas, and I realized we hadn't really talked about these that much in class.
A favela is a Brazilian slum. In the cities, they are extremely compact and feel like a labyrinth. The police usually have little to no control there, and usually, it is under control of one drug lord or another. They are almost completely different cities.
Here is a group of articles about life in favelas, and it also has a few pictures. Just click on them for a different article in the group.