Have you been having an uncontrollable obsession for feathers, sequins, and sexy dance costumes just perfect for performing the samba, Brazil’s national dance? Don’t fight it—it’s Carnival time, and your symptoms indicate a serious need to head south for the biggest party of the year.

Rio de Janeiro is South America’s sexiest city at any time, plying travelers with fantastic beaches, sultry nightlife, and a fantastic backdrop named one of the “Seven Wonders of the World.”

Forty days before Easter, things get even wilder. In anticipation of Lent’s deprivations, Rio’s mélange of cultures—European, African, and indigenous American, among many others—whip themselves into a glittering froth of music and madness. Though there are many such celebrations taking place around the globe, when most people say Carnival, they mean Rio de Janeiro.

The 2011 festivities kick off this Friday, March 4, with the biggest parties and parades scheduled for Saturday and Sunday. The culmination of countless balls, private parties, and other celebrations that take place from the favelas (shanty towns) to posh Zona Sul, comes on Fat Tuesday, drinking down the last drop of cachaça before Ash Wednesday rings in one holy hangover.

The main events take place at the Sambadrome, where a dozen top samba schools deck themselves out in flashy costumes and elaborate floats that they’ve been preparing all year. Each represents a neighborhood, and competition for the Carnival’s top prize is stiff. The 2011 festivities suffered an unfortunate setback this February, when a fire destroyed the work of three of Rio’s samba schools, causing some US$6 million in total damages.

“The fire burned everything,” said Helio de Oliveira, president of Academicos do Grande Rio, in an interview with New York Times, “but it didn’t burn our Carnival spirit.”

The show must—and will—go on, though no one yet knows what the schools that lost so much in the fire have planned. You can be sure, however, that a few flames won’t quench their thirst for enjoying the party.

It’s still probably still possible to score last-minute flights, hotel reservations (usually offered as five-day packages during Carnival), and steeply scalped tickets to the Sambadrome parades or Copacabana Palace balls, but savvy travelers are already planning for next year. We recommend making reservations at least four months out, particularly for top hotels in the beach neighborhoods.

Carnival lovers worldwide can check out the festivities live online, via several streaming live video services including SopCast and Justin.tv. For schedules of top events, tune into TV Globo, offering complete coverage of the entire extravaganza.