Spectators watching the Rio Olympics, which kick off Friday, will be hearing a cultural term used to describe pockets of neighborhoods surviving — and thriving — within Brazil's second-largest city: favela (pronounced fah-vel-ah).
It's origins date back to Brazil's civil war in 1897 when soldiers camped out in shacks on a hill where the favela plant grows in the northeast. After the war, some of the soldiers returned to Rio de Janeiro and were forced to settle on the forested hillsides when they weren't granted land promised by the government. Their makeshift living conditions were a reminder of the "favela" hills and the name eventually stuck.
Favela populations grew in the 19th century when slavery was abolished and surged in the 20th century as migration to Rio, the one-time capital of Brazil, became a draw for employment.
Today, there are an estimated 1,000 favelas in Rio, and they are home to about 1.5 million people, according to advocacy NGO Catalytic Communities.
Click through for more on the favelas.