Revelers enjoy the Carmelitas block party during Carnival celebrations Friday in Rio de Janeiro, Brazil.

Rio de Janeiro’s over-the-top Carnival that opened Friday is the highlight of the year for many local residents. Through Ash Wednesday, next week, hundreds of thousands of merrymakers will take to Rio’s streets in the nearly 500 open-air “bloco” parties.

The most traditional of these bashes is expected to attract more than 1 million people to Rio’s center area on Saturday.