The Anthology concludes the series of publications on the “Horizontal Metropolis,” a research and an oxymoron whose strength resides in expanding the traditional image of the metropolis to a larger territory where urban and non-urban elements live side by side, together with functions and infrastructures that transcend the local scale and help to shape, as a whole, new territorial relationships. The idea of metropolitan horizontality encompasses, and this is the second aspect tackled by the research, a project to overcome the traditional hierarchic relationships between territories, centres and peripheries, and the hypothesis of extending the benefits of multi-functionality, independence, and the possibility of making residential and work choices typical of a metropolitan context to traditionally servant territories. In the first case, the form of the city is discussed in terms of the heterogeneity of its physical and spatial construction, its disparate densities, co-existence between natural and urban elements and between agriculture and the city. The second dimension of the research looks at the structure of the relationships between the different parts and territories, the organizational logic of strong and weak infrastructures, the territorial distribution of the functions, the density of the accessibility and ecological mesh, and the detail of the hubs that mark the space and of the margins that can be rethought in terms of a horizontal design.