This paper presents the five acting domains within the concept of Smart City that are focused on transforming our cities into future cities, pursuing them to be able to compete themselves as a turism attraction. Among these domains, special mention to be made to those where civil engineers, thanks to their skills, have more presence. The paper is organized in five sections; firstly, the introduction about cities transformation and the change of concept they are suffering. Secondly, challenges that actual cities offer nowadays are presented, in the third section, windows of opportunity where to act on are detected, to focus in the fourth part, on those fields where the civil engineer performs the main roll, to end in the last section with a reflection about the need of acting on some other fields to reach the real city transformation.
