Represents the southern limit of the zone in the northern hemisphere that experiences a 24-hour period of sunlight and a 24-hour period of darkness at least once a year.

Arctic Circle

Explanation:

The arctic circle 66.56083N of the equator. It is one of the two polar circles and the most northerly of the five major circles of latitude. Eight countries can be found withing the arctic circle; Norway, Russia, Finland, United States(Alaska), Canada (Yukon, Northwest Territories, and Nunavut), Denmark (Greenland), and Iceland (where it passes through the small offshore island of Grímsey).