The Antarctic Circle at 66.5606 degrees S, the polar line that touches no sovereign country.
How this tool works
South of the Antarctic Circle the sun stays up for at least one full day each summer and stays down for at least one full day each winter. The line crosses only Antarctica itself, which is governed under the Antarctic Treaty rather than owned by any country. The map draws the line at its exact astronomical position on an equal-area style world map, and the table below it lists every country the line crosses. Entry points and approximate overland lengths are computed by intersecting the line with country boundary polygons, so the figures are estimates based on simplified boundaries rather than survey values.
What you can do with it
- See exactly where the circle sits around Antarctica
- Contrast it with the Arctic Circle, which crosses 8 national territories
- Use it to explain polar day and night in the southern hemisphere
- Reference the Antarctic Treaty context in the explainer
Why use it
Most maps show these lines as unlabeled dashes with no detail. If you want to know exactly which countries a line passes through, and for roughly how far, you usually end up cross-referencing several articles. This page puts the line, the country list, and the lengths in one place.