The shanty towns for which Rio Janeiro is famous (or notorious) play a pivotal role in the city's cultural history. Favelas, as they are known, rise precipitously from near the ocean far up the hillsides. Often bereft of minimal municipal services, they are home to a rich cultural life, their own social organization, and along the way in their history, have provided the artistic and dramatic talent for Brazil's most important international artistic contribution, Carnaval in Rio. David visits favelas and speaks with residents there.