A Map of the Bir Tawil "Triangle" and Related Territory Dispute Between Egypt and the Sudan
The Bir Tawil Triangle is likely the only unclaimed territory in the world. It is the result of a territorial dispute between Egypt and Sudan over the nearby Hala'ib Triangle. The original 1899 border between the two countries followed a straight line along the 22 degrees North latitude line. However the British drew up a new administrative border in 1902 that strays from the original border in several spots. The revised border gave an Egyptian tribe access to a well and grazing lands at Bir Tawil (Bir Tawil means water well). It also gave Sudan administrative control over the area marked Hala'ib Triangle because the dominant tribes in the region were Sudanese in origin.
Today, both countries lay claim to the Hala'ib Triangle since it is a large territory and borders the Red Sea. The problem comes from the intersection of the two borders at the Bir Tawil Triangle (actually a trapezoid). By claiming the original 1899 border to get Hala'ib, Egypt makes no claim on Bir Tawil which lies south of this border. Sudan pursues Hala'ib by claiming the 1902 border which leaves Bir Tawil as Egyptian territory. So in their pursuit of larger gains, each country makes no claim on the secondary territory. No other country can claim it as it is landlocked between Egypt and Sudan. There was a third territory adjusted in the 1902 adjustment called the Wadi Halfa Salient. That adjustment was made to assign several villages to Sudan who were better able to manage them from the South. Although the border remains, there is no territorial interest here as the villages now lie under the waters of the (manmade) Lake Nassar.