Weeks before Carnival officially kicked off, block parties sprung up all across Rio.
Rio's rich and famous gathered at extravagant balls, like this one at the Belmond Copacabana Palace hotel.
But the heart of Carnival is the multi-day parade in the Sambadrome.
Performers from 13 samba schools make their way through the open-air stadium in presentations filled with music, dancing, and elaborate, over-the-top costumes and floats.
next slide will load in 15 secondsSkip AdSkip AdEach school has a "drum queen" who dances non-stop to the rhythm of hundreds of drummers.
The parade is an explosion of color and culture.
Many schools pay tribute to Brazilian history and art. Below, performers parade in book-like costumes featuring the writings of Miguel Falabella.
This year's winner, Beija Flor, had a politically-charged performance that touched on corruption, crime, and violence.
Outside the Sambadrome, locals watch the festivities on TV.
next slide will load in 15 secondsSkip AdSkip AdThe Sambadrome parade date back to 1932.
Heavy clouds don't dampen the energy — the party rages on rain or shine.
Carnival traces its roots to an ancient Greek festival honoring Dionysus, the god of wine.
Each school's procession starts with the "comissão de frente" — a small group of performers who reveal their school's parade theme.
Then, the samba schools unveil their floats.
next slide will load in 15 secondsSkip AdSkip AdSome schools spend millions of dollars on their floats and costumes.
Every color of the rainbow is represented.
And several members of the animal kingdom, too.
Orchestras and bands play samba music while their schools are making their way down the aisle.
Rio's Carnival celebration dates back to the early 18th century. It marks the beginning of Lent for Catholics.
next slide will load in 15 secondsSkip AdSkip AdIn recent years, costumes and floats have been given a high-tech twist.
Yet some schools eschew technology in tributes to the indigenous people of Brazil.
Drum queens are usually actresses or models chosen for their looks, Samba skills and charisma.
The combination of sights, sounds, and electric energy combine for an unforgettable spectacle.