The Antarctic Circle is one of the five major circles of latitude that mark maps of the Earth. It is the parallel of latitude at 66° 33′ 39″ south of the Equator, crossing mostly the Southern Ocean.
In the Antarctic Circle, all places have twenty-four hours of daylight on the Summer Solstice in December. In June on the Winter Solstice all places have twenty-four hours of night. There is a minimum of one whole day that the sun does not set and one whole day that the sun does not rise.