In his seminal work, Halbwachs (1950: 132–139) already noted a homology between the resistance of stone and the resistance of cities’ inhabitants to being displaced or effaced. This contribution seeks to study the relationship between the built environment and residents’ collective memory in a historical area north-east of the Forbidden City, Gulou, which has recently been transformed by two successive urban renewal projects. The thickness of memory, where different realities and “fragments” (Marot 2010) coexist in the same space and create controversies in the way that territory is perceived, will be explored to emphasize the materiality of the memories that stand beside official public history. Indeed, in Gulou, legitimate forms of representation (Ricoeur 2000) – a late Qing historical map – have activated a specific memorial layer and institutional traces that has profoundly changed the urban fabric and generated displacement processes. The mobilization of collective memory will be illustrated through experiences of both analog and digital projects (ethnographic fieldwork, survey, digital monitoring website, blog, newsletter, social media group, etc.) carried out by the residents themselves and associations of local experts to preserve and map traces in the built environment to resist oblivion. These examples of alterations to the historic urban landscape (UNESCO 2011) in Beijing will finally illustrate the cultural heritage dynamics, usually defined as an ongoing redefinition of conservation practices, through specific memorial processes that paradoxically include the production, transformation, and disappearance of collective memory in its analog or digital dimension.