The Carnival in Rio de Janeiro is a festival held every year before Lent and considered the biggest carnival in the world with two million people per day on the streets. The first Carnival festival in Rio occurred in 1723.

The typical Rio carnival parade is filled with revelers, floats, and adornments from numerous samba schools which are located in Rio (more than 200 approximately, divided into five leagues/divisions). A samba school is composed of a collaboration of local neighbours that want to attend the carnival together, with some kind of regional, geographical and common background.

Rio’s Carnival begins on the Friday preceding Lent and ends on Ash Wednesday, but the Winners' Parade happens on Saturday after the carnival ends. The winning school and runners' up of the Special Group, as well as the A-Series champion, all march past one final time on this night.

More Info: en.wikipedia.org