In a cluster of villages in the mountains of central Sardinia, residents enjoy extraordinary longevity, particularly among males. Have genetics and lifestyle played a central role? Dan Buettner traveled to the Italian island to learn what makes Sardinians—especially those in the central region of Barbagia—some of the longest-lived people in the world.

Here, men pass a mural depicting a village procession. By keeping active, many men stay healthy longer. The unique geographic properties of central Sardinia—rocky, sun-beaten terrain not suited for large-scale farming—meant that over the centuries, shepherding offered the best profession. Walking five miles or more a day as Sardinian shepherds do provides cardiovascular benefits and has a positive effect on muscle and bone metabolism without the joint-pounding of running marathons or triathlons.

—Text adapted from the National Geographic book Blue Zones: Lessons for Living Longer From the People Who've Lived the Longest

Blue Zone Photos: Sardinia’s Secrets of Long Life

What gives the people of central Sardinia extraordinary longevity? Find out how genetics, lifestyle, and even laughter may all play a role.