"Is that snow?" my partner said one morning during a summer Mediterranean cruise as we opened our cabin's curtains to see a wide view of the Apuan Alps in Carrara, Italy. "No, it's marble," I said, smiling, because if I hadn't done my research, I would have thought the same thing.

The mountain range is home to the marble basin of Carrara in Tuscany. The marble in the Apuan Alps has been used since the Roman Empire for buildings and sculptures, according to UNESCO. Today, it's home to several marble quarries, and I got to see them for myself. The mountain range is home to some of the most coveted marble in the world, and it's dotted with marble quarries. I recently got a closer look during a group tour.