Terra Atomica is an emerging interdisciplinary platform uniting researchers, policymakers, artists, educators, and affected communities across Europe and beyond to collaboratively explore, document, and reinterpret the afterlives of nuclear landscapes. In a time of renewed nuclear anxiety, environmental uncertainty and misinformation, this COST Action aims to foster critical dialogue and promote ethical, sustainable, and creative approaches to Europe’s atomic heritage. The network addresses six interconnected areas: (1) mapping nuclear geographies and actors; (2) examining heritage policies and governance; (3) investigating transformations of nuclear sites through tourism, architecture, and environmental change; (4) analysing artistic, media, and digital representations; (5) rethinking nuclear heritage education; and (6) raising public awareness and promoting open, informed debate on nuclear legacies.Through working groups, virtual exhibitions, training schools, and public interventions, Terra Atomica will consolidate a new interdisciplinary field of nuclear heritage studies, developing shared methodological and pedagogical tools and producing policy recommendations for the responsible management of radioactive pasts. By connecting fragmented disciplines and amplifying long-marginalized voices, particularly from Eastern and Southeastern Europe, the Action will establish an equal, cross-regional dialogue on one of Europe’s most contested and enduring legacies. In doing so, Terra Atomica positions nuclear heritage as a vital arena for cultural activism, environmental responsibility, and social justice, shaping more inclusive and reflective futures for the Atomic age.