The ancient Greeks divided the world into climatic zones that are not accurate. The three zones included frigid, temperate, and torrid. They believed that civilized people could only live in the temperate zone (which, of course, was centered around Greece). From Europe northward was part of the inhospitable frigid zone, while most of Africa was torrid. Unfortunately, this three-zone classification system stuck and was later expanded to five zones once the southern hemisphere was explored. People identify everything north of the Arctic Circle (near northern Russia) and south of the Antarctic Circle (near the coast of Antarctica) as frigid, everything between the tropics and the Arctic and Antarctic circles as temperate, and the zone between the Tropic of Cancer and Capricorn as torrid.