Buenos Aires is a complex, chaotic city. It has European style and a Latin American heart. It has oscillated between dictatorship and democracy for over a century, and its citizens have faced brutal oppression and economic disaster.  Throughout all this, successive generations of activists and artists have taken to the streets of this city to express themselves through art. This has given the walls a powerful and symbolic role: they have become the city’s voice. This tradition of expression in public space, of art and activism interweaving, has made the streets of Buenos Aires into a riot of colour and communication, giving the world a lesson in how to make resistance beautiful.