Polar Point app for iPhone and iPad

In geography, the antipode of any spot on Earth is the point on Earths surface diametrically opposite to it; the antipodes of a region similarly represent the area opposite it. A pair of points antipodal to each other are situated such that a straight line connecting the two would pass through Earths center. Such points are as far away from each other as possible, a great-circle distance of 10,800 nautical miles (20,000 km).

In the Northern Hemisphere, "the Antipodes" may be used to refer to Australia and New Zealand, and "Antipodeans" to their inhabitants. Geographically, the antipodes of Britain and Ireland are in the Pacific Ocean, south of New Zealand. This gave rise to the name of the Antipodes Islands of New Zealand, which are close to the antipode of London at about 50°S 179°E. The antipodes of Australia are in the North Atlantic Ocean, while parts of Spain, Portugal, and Morocco are antipodal to New Zealand.

Approximately 15% of land territory is antipodal to other land, representing approximately 4.4% of the Earths surface. The largest antipodal land masses are the Malay Archipelago, antipodal to the Amazon Basin and adjoining Andean ranges; east China and Mongolia, antipodal to Chile and Argentina; and Greenland and the Canadian Arctic Archipelago, antipodal to East Antarctica. There is a general paucity of antipodal land because the Southern hemisphere has fairly little land, and of that, the antipodes of Australia are in the North Atlantic Ocean, while the antipodes of Africa are in the Pacific Ocean.