Bir Tawil is the disputed territory along the Egypt–Sudan border that is commonly described as terra nullius. Neither Egypt nor Sudan claims it under the boundary interpretation each country uses.
The unusual situation comes from two competing borders. An 1899 political boundary followed the 22nd parallel, while a 1902 administrative boundary reflected local tribal and governmental arrangements. Egypt relies mainly on the 1899 line, which favors its claim to the Hala'ib Triangle; Sudan relies on the 1902 line, which favors its claim to Hala'ib. Under those opposing positions, Bir Tawil falls to neither country.
Bir Tawil covers about 2,060 square kilometres and has no permanent settlements or access to the sea. Individuals have periodically announced micronations there, but no claim has received international recognition. The area is sometimes confused with the Hala'ib Triangle, which is the opposite case: both countries claim Hala'ib, while neither claims Bir Tawil. The term terra nullius is also a legal description, not proof that nobody has ever used or lived on the land; the Ababda people have traditional connections to the region.