The INFN 2025-2027 Three-Year Plan Study Days were held on 13 and 14 June. Hosted by the Lecce Division in the year of its 35th anniversary, the days focused on the great challenges. From the path towards a new management and research support model, to the INFN community and the prospects of research, from the European particle physics strategy to the Einstein Telescope, from neutrino physics to artificial intelligence, from quantum technologies to nuclear energy, and the future challenges of theoretical physics. Many challenges were presented and discussed: challenges that will engage the physics community in the coming years and challenges that our society will have to face, and which can be overcome with the contribution of physics. The Three-Year Plan days are the most awaited and attended annual event by the entire INFN community, because they represent a time for meeting and discussing many topics of transversal interest, both technical and scientific, as well as managerial and organisational.
