Is the Sea the Enemy? Occupation and Anthropogenic Impacts at Costa da Caparica (Portugal)

This article explores the development of human occupation and the anthropogenic impacts at Costa da Caparica, a Portuguese coastal town that faces several challenges concerning coastal erosion processes. A historical long-term analysis was made, mainly through medieval and modern writing sources, crossing such textual data with geology, geography, and other related scientific disciplines studies regarding the coastal erosion problems of the study area. Therefore, from the Middle Ages to the present, human actions concerning this area were examined. The sea was first seen as an income, due to tourism, and later seen as a danger. It is argued that human behaviors were the main cause of historical problems and also the present vulnerabilities and risks associated with this coastal stretch of the Portuguese littoral. We must search the past for answers to understand present problems and think about the future. This is the main purpose of this paper: to contribute to a better knowledge concerning coastal sustainability based on the results of past human actions, as a way to avoid such mistakes in the future.