The City as a non-Obvious Object of Sociology. The paper discusses some basic issues concerning the conceptualisation of the contemporary city, doing so from a sociological point of view. The author proposes an analytical perspective based on Lefebvre’s idea of the ‘production of space’ and on the study of urban territorialisation cycles. Following Harvey, three dimensions of space are considered: absolute, relative and relational. Starting from these dimensions, three different features of territorial capital are analysed: fixed, reticular and relative. However, the simple presence of these forms of territorial capital is not sufficient to define a city as a specific spatial object: in fact, it is also necessary that these resources become part of a project, shared by a large number of urban actors, to exploit this capital in order to pursue not only individual but also collective aims.