The documentary 31 Islands on the Island. The case of Sardinia tells the phenomenon of depopulation through a 10-day bicycle trip. Inspired by the reading of the essay "SPOP, instant depopulation in Sardinia", an accurate study conducted by the Sardarch collective of Cagliari, Franco Loriga traced a route through the 31 countries with the highest percentage of depopulation. The phenomenon, now growing throughout Europe, particularly affects the internal areas of the Sardinia Region and directly involves over 250 municipalities. Structured on two independent but closely connected lines, the documentary develops with meticulous alternation between the travel images and the numerous interviews with illustrious personalities and experts on the phenomenon of depopulation which, through personal ideas and opinions, expose hypotheses useful to contrast the social condition and demographic. In addition to interviews, the documentaries are characterized by images that highlight the extraordinary landscapes found throughout the territory of Sardinia and the numerous works of historical and cultural interest crossed during the journey. A document of common interest that, in addition to showing a "new" reality, highlights possible alternatives for socio-cultural development.