The 45×90 points are the four points on Earth which are both halfway between one of the geographical poles and the equator, and halfway between the Prime Meridian and the 180th meridian. Both northern 45×90 points are located on land, while both southern 45×90 points are in remote open ocean locations.
The best-known and most frequently visited such point is 45°N -90°W, which is 1345abbr=onNaNabbr=on above sea level in the town of Rietbrock, Wisconsin near the unincorporated community of Poniatowski. A grand board and precise metal ground marker was placed by the Marathon County Park Commission, only to be relocated slightly[1] and restored to visitor access since September 12, 2017.[2]
The former marker has been replaced by a small parking lot with a trail that leads to a long, rectangular park. The Geographical Marker is at the southern end of the park along with informational displays.
The point has become something of a pop culture phenomenon thanks to Gesicki's Tavern in the tiny cluster of establishments in Poniatowski.[3] They sold 45×90 T-shirts and registered visitors as members of the "45×90 Club".[3] Since 2006, the Wausau/Central Wisconsin Convention & Visitors Bureau has been the holder of the official "45×90 Club" registration book. The book is on loan from the family.[4] On becoming a member of the club, the Bureau gives a commemorative coin.
The only other 45×90 point located on land is 45°N 90°W, which is at an elevation of 3311abbr=onNaNabbr=on above sea level. This point is located in a desolate region of the Xinjiang Uyghur Autonomous Region of China, near the Mongolian border, approximately 240km (150miles) northeast of Ürümqi. Administratively, it is on the border of Qitai and Qinggil counties. Greg Michaels, an American, and Ru Rong Zhao, a taxi driver from the closest town of Qitai, which is 110 km to the south-southwest, visited this point on April 13, 2004 and documented the visit on the Degree Confluence Project.[5] Their visit found no monument or any physical recognition of the status and documented that the nearest community to the site documented on maps, Jiangjunmiao, had long since been abandoned.
In the southern Indian Ocean, -45°N 90°W has an ocean floor depth of 10489abbr=onNaNabbr=on below sea level and is: 773order=flipNaNorder=flip southeast of the nearest (uninhabited) island of Île Saint-Paul; 920order=flipNaNorder=flip northeast of Elephant Spit, Heard Island; 975order=flipNaNorder=flip east northeast of the small village-like capital Port aux Français of the Kerguelen Islands; 1507order=flipNaNorder=flip north of Antarctica; 1521order=flipNaNorder=flip southwest of Augusta, Western Australia, 2535order=flipNaNorder=flip southeast of Réunion Island, and 3450order=flipNaNorder=flip southeast of Benguerra Island, Mozambique, and 3600order=flipNaNorder=flip southeast of Mossel Bay, South Africa.
In March 2014, the point was in one of a few strips in a search for the missing Malaysia Airlines Flight 370, after potential debris were spotted by satellite about there.[6] [7]
Located in the southern Pacific Ocean, 806order=flipNaNorder=flip west south west of Guaitecas in Chile, and 1910order=flipNaNorder=flip north of Antarctica, -45°N -90°W has an ocean floor depth of 13730abbr=onNaNabbr=on below sea level.
Each 45×90 point is the antipodethe point on the opposite side of Earthof another 45×90 point.
The southern Indian Ocean location and the point in Wisconsin are antipodes of each other. The southern Pacific Ocean location and the point in China are antipodes of each other.