On the Earth, the small circle located at 66.5 degrees south latitude, which is 23.5 degrees latitude north of the Earth's south pole. Below this latitude, the summer Sun never sets, and the winter Sun never rises. See also Arctic Circle
The line of latitude 66Â°34â€²S (often taken as 66 Along this line the sun does not set on the day of the summer solstice, about 22 December, and does not rise on the day of the winter solstice, about 21 June.
The parallel of latitude approximately 66°30' south. This parallel marks the northern limit of the area within which for at least one day each year the Sun does not set or rise (about June 21st). It forms the boundary between the South Temperate and South Frigid zones.