Urbane Praxis rethinks urban development and draws on the potential of freely available (public) spaces in our cities. But how can such spaces be identified? And are all spaces that look „free“ really „public“? Using an app developed by Radical Data, Guerilla Architects explored public and pseudo-public space in an exemplary piece of Berlin – around Mercedes Benz Platz – together with participants and made them aware of its boundaries and limitations. The walks served to sharpen the participants‘ perception of the city and thus to direct their gaze to the traces of privatization.