Carnival in Rio de Janeiro.
Carnival is Rio's defining event — a week when the entire city stops for music, costume and dance. There are really two Carnivals happening at once: the free, chaotic, joyful street parties called blocos that move through every neighbourhood, and the ticketed, world-famous samba-school parades in the purpose-built Sambódromo. Most visitors do some of both.
The date moves each year because it's tied to the church calendar — Carnival runs in the days before Lent, which puts it in February or early March. Below is what each half is like, and how to be here for it.