Urban Void is an open group of architects and artists working on collective actions in the city of Athens. Since 1998 the group has performed 13 actions in the urban context involving the active participation of the public. These events include walking, announcing texts and other simple everyday acts organized by the group on the sites of interest. Simply through their presence on the sites, Urban Void members invite the citizens to activate these neglected areas of the city. These empty fields are places in limbo undergoing changes and transformations, urban spaces characterized by ambiguity in respect to their identity, use or legal status. By temporality inhabiting these spaces, Urban Void is testing the relationship of the sites to the citizens and the city life.