A community of 2,400 people, Silanus is located on the edge of a mountainous region in central Sardinia, where dry fields rise suddenly into mountains of stone. In a group of villages in the heart of the region, which scientists call the"Blue Zone," 91 of the 17,865 people born between 1880 and 1900 have lived to their hundredth birthday-a rate more than twice as high as the average for Italy.