Matera: a magical and unique stone city that has been chosen as a natural set for several films (such as Mel Gibson's "Passion of Christ") with its two old areas called Sassi (which means stones): Sasso Caveoso and Sasso Barisano . The Sassi of Matera were declared, in 1993, a UNESCO World Heritage Site because they represent "the most exceptional and intact" example of a troglodyte settlement in the Mediterranean region, perfectly integrated into its own ecosystem.