A helicopter transports material at the Candoglia Quarry on December 5, 2024. Orginally the blocks of marble were transported via the waterways on the Toce River to Lake Maggiore, then along the Ticino River and the Naviglio Grande canal, eventually reaching, through a system of locks Via Laghetto, located just a few hundred meters from the Cathedral’s construction site in the city center. Marble workers of the "Venerable Factory of the Duomo of Milan" (Fabbrica del Duomo) are taking care of more than 3.000 statues and gargoyles sculpted in marble from Candoglia quarries in the Italian Alps. (Photo by Piero CRUCIATTI / AFP)