In 1984, a research project commissioned by UNESCO's MAB Programme pioneered academic work on people-environment interaction. The project has been focusing on the city's interrelationships with its river, in different approaches ranging from the perception of environmental quality to ecologically sustainable development opportunities. One of the positive contributions of the project was the insertion of environmental perception in the methodological approach employed in urban analysis, in order to obtain deeper contextual information about the environment and to use this information to enhance the issuing of design strategies. In its 1986 phase, the project allowed for the identification of major structural components of the central area's urban landscape, as perceived by their users. At present, after a decade of decisive change in ways of life and of perceiving values, and after implementation of design policies for historical and cultural sets in the central core, people's views of the centre have been reexamined. New research, also employing environmental perception techniques, collected the repertoire of cultural elements as seen today by the population at large and by selected microcultural groups. This perception, when compared to official listings produced by experts, although convergent in several items, revealed the issuing of new elements. The emergence of elements in people's perception indicate how changing ways of life and different levels of education are significant for design guidelines in the presence of evolving values and environmental ideals.