Bir Tawil or Bi'r Tawīl (بيرطويل in Arabic; Bi'r or بير, meaning "tall water well") is a 2,060 km2 (795 sq mi) area along the border between Egypt and Sudan which is claimed by neither country. It is sometimes referred to as the Bir Tawil Triangle, despite the area's quadrilateral shape, with the longer side in the north of the area running along the 22° north circle of latitude. It is the only area where the administrative boundary of 1902 between the two countries runs south of the political boundary of 1899, which had been defined as the 22° north circle of latitude. East-to-west, the area is between 46 kilometres (29 mi) long in the south, and 95 kilometres (59 mi) long in the north, and between 26 kilometres (16 mi) and 31 kilometres (19 mi) wide north-to-south, and 2,060 km2 (800 sq mi) in size.
The Bir Tawil area came under Egyptian administration in 1902, because it was grazing land of the Ababda tribe based near Aswan, Egypt. At the same time, the Hala'ib Triangle north of latitude 22° north, and northeast of the area, came under Sudanese administration, because the tribes of this area were based in Sudan. The two "triangles" border at one point, a quadripoint. Egypt still administers the territory, but it is not marked as Egyptian on government maps.