Cities have been designed according to their needs and challenges—i.e., structural, social, and technological advances. The city can be understood as a centre where our past, present, and future coexist. Furthermore, cities reflect the actual tendencies and directions, as exemplified by globalization and cross-border cooperation. Similarly, the creation of Eurocities in Iberian Peninsula territories can be an example how these processes can be implement and use the territories’ development, based on shared resources of neighbouring cities. Contextually, the paper addresses not only urban planning models as well as Eurocities case studies, but also projects of planning and territorial management within Iberian Territories—i.e., of the cross-border cooperation projects and strategies. Throughout the present research it was possible to understand the creation and genesis of Eurocities projects and strategies. Furthermore, the research was able to define a timeline of the process of urban and common planning carried out on the Iberian Peninsula, from the past to the present. Moreover, the study reveals the disadvantages or obstacles present during the Eurocities creation, as well as some interactions among planning methodologies, tools, and public policies and the Eurocities conception on the Iberian Peninsula.