This talk explores the lost or erased heritage of Nou Barris and the urban transformation processes that have shaped the district's various neighborhoods. It focuses on the relationship between the physical remnants that have endured, what has vanished, and the impact of these absences on collective memory and territorial identity. Through a plural perspective, the session will reflect on urban interventions, demolitions, rehabilitations, and the fragility of certain environments, emphasizing the need to broaden the concept of heritage by incorporating social, historical, and sustainability dimensions. The session is structured around four brief contributions and an open debate with the audience, facilitated by Nirvana Amaya, an art historian and Nou Barris resident. Guest speakers include Jordi Sánchez from the Roquetes Historical Archive, Júlia Brull Palou from Oasiurbà, and Angie and Camila from Descoloniza BCN Tour.