The Menéndez Pelayo International University (UIMP), the Port Authority of Santander and Rete, the International Association for Collaboration between Ports and Cities, have presented in Santander the book 'The port city of the XXI-new challenges in the Puerto-city relationship '. In the presentation of the book, produced and edited by the Rete Association, were the president of the same association and of the Port Authority of Santander, José Joaquín Martínez Sieso, the architect and director of the Scientific Committee of the same Society, Rinio Bruttomessso, and The Vice Chancellor for Academic Planning of the UIMP, Mº Cruz Díaz. Under the coordination of Rinio Bruttomsso and Joan Alemany, this volume offers an interdisciplinary look that analyzes the dynamics that have marked the recent worldwide future of port cities as well as the problems and challenges facing this unique type of urban centers. In the act, Bruttomsso highlighted the "strategic" relationship between the port and the city for the future of both and the need for all parties, from the City Council to the other institutions, to be involved in a topic "that belongs to everyone" . On the other hand, he emphasized the work of the book, which began to be elaborated in 2009 and that represents an "interdisciplinary look" on the reality of port cities. Martínez Sieso took a tour of the ten years of life of the Rete Association, which "seeks to promote the activity and collaboration between port cities", and explained the three types of activities carried out by the association such as training and training, research and generation of specialized knowledge, and transmission and dissemination of knowledge. For his part, Díaz influenced the joint work between the port and the UIMP regarding courses carried out and in the work of the Port Authority in the field of research and knowledge, as well as in "the look towards the new challenges." The work is a collective work that reflects on the contemporary port city, the keys and components of the Puerto-Ciudad relations, as well as the dynamics that have marked the recent world future of this unique typology of urban centers. It is a publication as a result of the collective work of twenty -eight authors and the institutional collaboration in which they have participated about thirty specialists from Europe, the United States, Latin America and Japan, among which academics and professionals of recognized prestige stand out.