Antarctic Circle

Everything south of this circle is known as the Antarctic, and the zone to the north is the Southern Temperate Zone.

This is the parallel of latitude that runs approximately 66.5° south of the Equator. Within the Antarctic Circle, the Sun is above the horizon for, at least, 24 continuous hours per year, in conjunction with the Summer Solstice. Likewise, in conjunction with the antarctic Winter Solstice, the sun is below the horizon for, at least, 24 continuous hours.