Audio slideshow: Faces of the favelas
The French artist JR first made his mark in Rio de Janeiro last year, as giant posters of staring eyes started appearing on buildings in the city's oldest favela.
He was drawn there following the controversial deaths of three young men, amid alleged collusion between Brazilian soldiers and a drugs gang.
But now JR's work has made it on to some of Rio's grander structures. Take a tour of the city with the artist himself, and meet the people who inspired him.