If you take a stroll one sunny Sunday morning through the peripheries of Barcelona you’ll come across a strange landscape. Between the motorways and housing blocks, the industrial states, the commercial centres and sports complexes; between the nature parks and the theme parks, at the edge of all this contemporary urbanization, you will find the marginal areas where folk flock together every weekend to spend their free time. The question is: Why do people turn these residual spaces into the centre of their leisure activity?