This lecture introduces the concept of Groundscape, focusing on the potential of the underground city landscape. The instructor discusses strategies to utilize and make visible the underground domain, emphasizing sustainable development. Through examples like the Arc de Triomphe in Paris, the lecture explores how introducing light underground can revitalize historical monuments, create new spaces, and foster diverse activities, connecting the past with contemporary urban life. The Groundscape strategy aims to enhance the relationship between heritage, the city, and its inhabitants, proposing a multi-dimensional solution that integrates social, economic, political, historical, architectural, and aesthetic aspects.