The common denominator amongst urban neighbourhoods participating to the SUN project is that they were impacted by the rapid growth and then by the decline of industries. Today, despites public supporting policies, they still suffer from a comparative lack of environmental quality, they remain perceived, often wrongly, as insecure neighbourhoods, and finally they concentrate poorest populations. Yet they possess unsuspected assets, that the SUN project wants bringing to light: their multi-culturality, a very dynamic associative network, or still talents recongnized well beyond the limits of their neighbourhood.