Ria de Aveiro is a remarkable estuarine lagoon located on the Northern coast of Portugal, and it is divided from the Atlantic Ocean by a sand bar. It presents a very complex and variable landscape, due to its intense influence of tidal fluctuations and coastal circulations. The peculiar strong marine influence supported the development and consolidation of a multitude of biotopes of great ecological importance related to variety in water salinity patterns and gradients found in the lagoon. In recent years, the lagoon is experiencing an intensification of the landscape dynamics, resulting into a constantly growing risk of flooding in agricultural fields, natural areas and even in the historical centre of Aveiro. This Research - Through - Designing aimed to investigate the relation between the landscape and the dynamics affecting the lagoon to reduce the impact and risk of flooding in Ria de Aveiro, intended as a whole. Through the use of a hydrodynamic model developed by NMEC Lab in Aveiro, the flood risk for 2100 has been predicted. Three different approaches are discussed and tested through the hydrodynamic model to assess the effectivity of the possible solutions towards the flood risk in 2100; amongst these possible options, it has been chosen and developed the option which ensures protection while at the same time gives opportunities for improving the quality of the landscape. The revival of the disappearing landscapes of the lagoon is then presented in a design which aims to explore and exploit the multitude.