From 2009, Rio de Janeiro has been building walls around some of its favelas, the shanty towns that crowd the hills around the city.
In total, 13 favelas will eventually be surrounded by concrete with a total length of 14km and a height varying between 80cm and 3m. It will spend 40 million reais ($17.6 million) and have to relocate 550 houses.
Icaro Moreno, president of the state’s public works department, explained that this was to stop deforestation of the Atlantic rain forest which surrounds Rio, one of the largest urban nature reservations in the world.
Human rights groups claim that the walls have been built to keep residents of the favela segregated from the rest of Rio society. Others say they are intended to limit drug trafficking, as part of a planned regional government clamp down.