On the occasion of the 50th anniversary of the Centro de Cálculo of Madrid’s University, it is offered a review of some of the alternative city proposals made by the architect Juan Navarro Baldeweg during his stay at the Centre, in the middle of the 1960s, which seem to anticipate some of the ideas associated nowadays to what has come to be known as smart cities. These ideas prioritized greater community involvement in shaping the city, as well as the use of new technologies for the design of more connected, efficient, affordable and sustainable cities.