Looking closely at this picture, at first glance, it's not a pretty sight, a sprawling shanty town in Rio de Janeiro. On second glance, it's something else entirely. Art, to be precise, courtesy of French photographer and guerilla artist JR.

JR is best known for photographing people with a 28mm camera he found on the underground, and covertly posting the images around their hometowns. His guerilla style has been described as possessing a quailty of 'in-your-face rudeness'.

He's just spent a month in a historical - but dangerous - favela district of Rio, where recently three teenagers were killed in a clash with corrupt local authorities. With the help of local photographer Mauricio Hora, JR photographed women of all backgrounds and ages who are caught up in a constant daily struggle. His installation, called 28 Millimetres: Women, was posted with their help.

JR's work is prolific, and has graced walls from Paris to Berlin, London (this video shows you how it's done) to Cartagena, Spain. Women is a global project, with sister projects in Sierra Leone, Libera and Sudan, with Asian countries being added soon.