A blue zone is a region in the world where people are claimed to have exceptionally long lives beyond the age of 80 due to a lifestyle combining physical activity, low stress, rich social interactions, a local whole-foods diet, and low disease incidence. Examples of blue zones include Okinawa Prefecture, Japan; Nuoro Province, Sardinia, Italy; the Nicoya Peninsula, Costa Rica; and Icaria, Greece. The name "blue zones" derived simply during the original survey by scientists, who "used a blue pen on a map to mark the villages with long-lived population."