Arctic Circle
The Arctic Circle is one of the two polar circles and the most northerly of the five major circles of latitude as shown on maps of Earth. It marks the northernmost point at which the center of the noon sun is just visible on the December solstice and the southernmost point at which the center of the midnight sun is just visible on the June solstice. The region north of this circle is known as the Arctic, and the zone just to the south is called the Northern Temperate Zone. As seen from the Arctic, the Sun is above the horizon for 24 continuous hours at least once per year and below the horizon for 24 continuous hours at least once per year. This is also true in the Antarctic region, south of the equivalent Antarctic Circle. The position of the Arctic Circle is not fixed and currently runs 66°33′48.4″ north of the Equator.
