The nature of limit. The coastline between artifice and nature

The article presents a "two voices" talk on the topic of border. The thought of an environmental designer (Rigillo), strongly oriented to develop an ecological approach to the urban waterfront, and the thinking of an urban designer (Santangelo), interested in reading the urban waterfront not only as topographic matter, but as generative condition that marks profoundly the city shape and its destiny. In this meaning the concept of limit - in the sequence of sea /land /settlement - is focused on exploring the reciprocal relationship between the architecture of the city and its coastline, looking at the history (graphics) of the urban transformation and to the environmental specificities that have generated it. The paper proposes a double reading of the coastline as cultural landscape, resulting from the adaptation between the specificity of native ecosystems and the human needs. The cost line is a prime ecological infrastructure that the city - in a renewed culture of limits - must be able to understand and use. Through the analysis of the coastal environment and its architecture, the paper provides a set of theorical consideration that lead towards new cultural awareness by the aim of developing new opportunities for the sustainable city project. The gaze is directed to the project, learning from the past and open to the future, by the goal of controlling sensitive performances to re-create an artificial landscape consistent with the morphological and ecological features of the site, adding meaning and quality in its articulation of new forms and reports to the needs expressed by the city.