On Friday 29 September, starting from 6pm, the INFN Milan Division, with the support of the Italian Physics Students Association, will participate in the open night of the "Leonardo da Vinci" Museum of Science and Technology, where it will offer a vast range of activities: guided tours of the Extreme exhibition, live measurements of natural radioactivity and cosmic rays with different detectors, including a new "cosmic shower", games, Lego bricks to tell about nuclear isotopes and other initiatives to tell about the research activities of our institution. Entrance is free.