What is Carnival? Carnival is the largest annual festival in Brazil, a week-long celebration held in various cities all over the country, with parades and parties day and night. Traditions differ from city to city; however, each of the celebrations encorporates rhythm, dance and costumes, with the most traditional dance being samba. In Rio de Janeiro, the famous Samba schools of the city parades in Sambadrones or floats throughout the city, as in the photo to the right.